description: You are given a sequence a_1, a_2, ..., a_n consisting of n pairwise distinct positive integers.
  
  Find \left⌊ \frac n 2 \right⌋ different pairs of integers x and y such that: 
  
    * x ≠ y; 
    * x and y appear in a; 
    * x~mod~y doesn't appear in a. 
  
  
  
  Note that some x or y can belong to multiple pairs.
  
  ⌊ x ⌋ denotes the floor function — the largest integer less than or equal to x. x~mod~y denotes the remainder from dividing x by y.
  
  If there are multiple solutions, print any of them. It can be shown that at least one solution always exists.
  
  Input
  
  The first line contains a single integer t (1 ≤ t ≤ 10^4) — the number of testcases.
  
  The first line of each testcase contains a single integer n (2 ≤ n ≤ 2 ⋅ 10^5) — the length of the sequence.
  
  The second line of each testcase contains n integers a_1, a_2, ..., a_n (1 ≤ a_i ≤ 10^6).
  
  All numbers in the sequence are pairwise distinct. The sum of n over all testcases doesn't exceed 2 ⋅ 10^5.
  
  Output
  
  The answer for each testcase should contain \left⌊ \frac n 2 \right⌋ different pairs of integers x and y such that x ≠ y, x and y appear in a and x~mod~y doesn't appear in a. Print the pairs one after another.
  
  You can print the pairs in any order. However, the order of numbers in the pair should be exactly such that the first number is x and the second number is y. All pairs should be pairwise distinct.
  
  If there are multiple solutions, print any of them.
  
  Example
  
  Input
  
  
  4
  2
  1 4
  4
  2 8 3 4
  5
  3 8 5 9 7
  6
  2 7 5 3 4 8
  
  
  Output
  
  
  4 1
  8 2
  8 4
  9 5
  7 5
  8 7
  4 3
  5 2
  
  Note
  
  In the first testcase there are only two pairs: (1, 4) and (4, 1). \left⌊ \frac 2 2 \right⌋=1, so we have to find one pair. 1~mod~4=1, and 1 appears in a, so that pair is invalid. Thus, the only possible answer is a pair (4, 1).
  
  In the second testcase, we chose pairs 8~mod~2=0 and 8~mod~4=0. 0 doesn't appear in a, so that answer is valid. There are multiple possible answers for that testcase.
  
  In the third testcase, the chosen pairs are 9~mod~5=4 and 7~mod~5=2. Neither 4, nor 2, appears in a, so that answer is valid.
solution: 
  import java.io.*;
  import java.lang.reflect.Array;
  import java.math.BigInteger;
  import java.util.*;
  
  public class Main {
  
      static class Pair {
          int l,r;
  
          public Pair(int l,int r) {
              this.l=l;
              this.r=r;
          }
      }
  
      static int mod=1000000007;
  
      public static void main(String[] args) throws IOException
      {
          InputStream inputStream = System.in;
          OutputStream outputStream = System.out;
          InputReader in = new InputReader(inputStream);
          OutputWriter out = new OutputWriter(outputStream);
          TaskC solver = new TaskC();
          solver.solve(1, in, out);
          out.close();
      }
  
      static class TaskC
      {
          public static void solve(int testNumber, InputReader in, OutputWriter out)
          {
              int t=in.readInt();
              while(t-->0)
              {
                  int n=in.readInt();
                  int arr[]=in.nextIntArray(n);
                  CP.sort(arr);
                  int cnt=0,val=n/2;
                  for(int i=1;i<n;i++)
                  {
                      if(cnt<val)
                      {
                          out.printLine(arr[i]+" "+arr[0]);
                          ++cnt;
                      }
                      else
                      {
                          break;
                      }
                  }
              }
          }
      }
  
      static class InputReader {
          private InputStream stream;
          private byte[] buf = new byte[1024];
          private int curChar;
          private int numChars;
          private InputReader.SpaceCharFilter filter;
  
          public InputReader(InputStream stream) {
              this.stream = stream;
          }
  
          public int read() {
              if (numChars == -1) {
                  throw new InputMismatchException();
              }
              if (curChar >= numChars) {
                  curChar = 0;
                  try {
                      numChars = stream.read(buf);
                  } catch (IOException e) {
                      throw new InputMismatchException();
                  }
                  if (numChars <= 0) {
                      return -1;
                  }
              }
              return buf[curChar++];
          }
  
          public int readInt() {
              int c = read();
              while (isSpaceChar(c)) {
                  c = read();
              }
              int sgn = 1;
              if (c == '-') {
                  sgn = -1;
                  c = read();
              }
              int res = 0;
              do {
                  if (c < '0' || c > '9') {
                      throw new InputMismatchException();
                  }
                  res *= 10;
                  res += c - '0';
                  c = read();
              } while (!isSpaceChar(c));
              return res * sgn;
          }
  
          public int[] nextIntArray(int arraySize) {
              int[] array = new int[arraySize];
  
              for (int i = 0; i < arraySize; i++) {
                  array[i] = readInt();
              }
  
              return array;
          }
  
          public String readString() {
              int c = read();
              while (isSpaceChar(c)) {
                  c = read();
              }
              StringBuilder res = new StringBuilder();
              do {
                  if (Character.isValidCodePoint(c)) {
                      res.appendCodePoint(c);
                  }
                  c = read();
              } while (!isSpaceChar(c));
              return res.toString();
          }
  
          public boolean isNewLine(int c) {
              return c == '\n';
          }
  
          public String nextLine() {
              int c = read();
  
              StringBuilder result = new StringBuilder();
  
              do {
                  result.appendCodePoint(c);
  
                  c = read();
              } while (!isNewLine(c));
  
              return result.toString();
          }
  
          public long nextLong() {
              int c = read();
  
              while (isSpaceChar(c)) {
                  c = read();
              }
  
              int sign = 1;
  
              if (c == '-') {
                  sign = -1;
  
                  c = read();
              }
  
              long result = 0;
  
              do {
                  if (c < '0' || c > '9') {
                      throw new InputMismatchException();
                  }
  
                  result *= 10;
                  result += c & 15;
  
                  c = read();
              } while (!isSpaceChar(c));
  
              return result * sign;
          }
  
          public long[] nextLongArray(int arraySize) {
              long array[] = new long[arraySize];
  
              for (int i = 0; i < arraySize; i++) {
                  array[i] = nextLong();
              }
  
              return array;
          }
  
          public double nextDouble() {
              double ret = 0, div = 1;
              byte c = (byte) read();
  
              while (c <= ' ') {
                  c = (byte) read();
              }
  
              boolean neg = (c == '-');
  
              if (neg) {
                  c = (byte) read();
              }
  
              do {
                  ret = ret * 10 + c - '0';
              } while ((c = (byte) read()) >= '0' && c <= '9');
  
              if (c == '.') {
                  while ((c = (byte) read()) >= '0' && c <= '9') {
                      ret += (c - '0') / (div *= 10);
                  }
              }
  
              if (neg) {
                  return -ret;
              }
  
              return ret;
          }
  
          public boolean isSpaceChar(int c) {
              if (filter != null) {
                  return filter.isSpaceChar(c);
              }
              return isWhitespace(c);
          }
  
          public static boolean isWhitespace(int c) {
              return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1;
          }
  
          public interface SpaceCharFilter {
              public boolean isSpaceChar(int ch);
  
          }
      }
  
      static class CP {
  
          static boolean isPrime(long n) {
              if (n <= 1)
                  return false;
              if (n == 2 || n == 3)
                  return true;
              if (n % 2 == 0 || n % 3 == 0)
                  return false;
              for (int i = 5; (long) i * i <= n; i += 6) {
                  if (n % i == 0 || n % (i + 2) == 0)
                      return false;
              }
              return true;
          }
  
          static String addChar(String s, int n, String ch) {
              String res =s+String.join("", Collections.nCopies(n, ch));
              return res;
          }
  
          static int ifnotPrime(int[] prime, int x) {
  
              return (prime[x / 64] & (1 << ((x >> 1) & 31)));
          }
  
          static void makeComposite(int[] prime, int x) {
  
              prime[x / 64] |= (1 << ((x >> 1) & 31));
          }
  
          static ArrayList<Integer> bitWiseSieve(int n) {
              ArrayList<Integer> al = new ArrayList<>();
              int prime[] = new int[n / 64 + 1];
  
  
              for (int i = 3; i * i <= n; i += 2) {
  
                  if (ifnotPrime(prime, i) == 0)
                      for (int j = i * i, k = i << 1;
                           j < n; j += k)
                          makeComposite(prime, j);
              }
  
              al.add(2);
  
              for (int i = 3; i <= n; i += 2)
                  if (ifnotPrime(prime, i) == 0)
                      al.add(i);
  
              return al;
          }
  
          public static long[] sort(long arr[]){
              List<Long> list = new ArrayList<>();
              for(long n : arr){list.add(n);}
              Collections.sort(list);
              for(int i=0;i<arr.length;i++){
                  arr[i] = list.get(i);
              }
              return arr;
          }
  
  
          static ArrayList<Integer> sieve(long size) {
  
              ArrayList<Integer> pr = new ArrayList<Integer>();
              boolean prime[] = new boolean[(int) size];
              for (int i = 2; i < prime.length; i++) prime[i] = true;
              for (int i = 2; i * i < prime.length; i++) {
                  if (prime[i]) {
                      for (int j = i * i; j < prime.length; j += i) {
                          prime[j] = false;
                      }
                  }
              }
              for (int i = 2; i < prime.length; i++) if (prime[i]) pr.add(i);
              return pr;
          }
  
          static ArrayList<Integer> segmented_sieve(int l, int r, ArrayList<Integer> primes) {
              ArrayList<Integer> al=new ArrayList<>();
              if (l == 1) ++l;
              int max = r - l + 1;
              int arr[] = new int[max];
              for (int p : primes) {
                  if (p * p <= r) {
                      int i = (l / p) * p;
                      if (i < l) i += p;
                      for (; i <= r; i += p) {
                          if (i != p) {
                              arr[i - l] = 1;
                          }
                      }
                  }
              }
              for (int i = 0; i < max; ++i) {
                  if (arr[i] == 0) {
                      al.add(l+i);
                  }
              }
              return al;
          }
  
          static boolean isfPrime(long n, int iteration) {
  
              if (n == 0 || n == 1)
                  return false;
  
              if (n == 2)
                  return true;
  
              if (n % 2 == 0)
                  return false;
  
              Random rand = new Random();
              for (int i = 0; i < iteration; i++) {
                  long r = Math.abs(rand.nextLong());
                  long a = r % (n - 1) + 1;
                  if (modPow(a, n - 1, n) != 1)
                      return false;
              }
              return true;
          }
  
          static long modPow(long a, long b, long c) {
              long res = 1;
              for (int i = 0; i < b; i++) {
                  res *= a;
                  res %= c;
              }
              return res % c;
          }
  
          private static long binPower(long a, long l, long mod) {
  
              long res = 0;
  
              while (l > 0) {
                  if ((l & 1) == 1) {
                      res = mulmod(res, a, mod);
                      ;
                      l >>= 1;
                  }
                  a = mulmod(a, a, mod);
              }
              return res;
          }
  
          private static long mulmod(long a, long b, long c) {
  
              long x = 0, y = a % c;
              while (b > 0) {
                  if (b % 2 == 1) {
                      x = (x + y) % c;
                  }
                  y = (y * 2L) % c;
                  b /= 2;
              }
              return x % c;
  
          }
  
          static long binary_Expo(long a, long b) {
              long res = 1;
              while (b != 0) {
                  if ((b & 1) == 1) {
                      res *= a;
                      --b;
                  }
                  a *= a;
                  b /= 2;
              }
              return res;
          }
  
          static long Modular_Expo(long a, long b) {
              long res = 1;
              while (b != 0) {
                  if ((b & 1) == 1) {
                      res = (res * a) % 1000000007 ;
                      --b;
                  }
                  a = (a * a) % 1000000007;
                  b /= 2;
              }
              return res%1000000007;
          }
  
          static int i_gcd(int a, int b) {
              while (true) {
                  if (b == 0)
                      return a;
                  int c = a;
                  a = b;
                  b = c % b;
              }
          }
  
          static long gcd(long a, long b) {
              if (b == 0)
                  return a;
              return gcd(b, a % b);
          }
  
          static long ceil_div(long a, long b) {
              return (a + b - 1) / b;
          }
  
          static int getIthBitFromInt(int bits, int i) {
              return (bits >> (i - 1)) & 1;
          }
  
          private static TreeMap<Long, Long> primeFactorize(long n) {
              TreeMap<Long, Long> pf = new TreeMap<>(Collections.reverseOrder());
              long cnt = 0;
              long total = 1;
              for (long i = 2; (long) i * i <= n; ++i) {
                  if (n % i == 0) {
                      cnt = 0;
                      while (n % i == 0) {
                          ++cnt;
                          n /= i;
                      }
                      pf.put(cnt, i);
                      //total*=(cnt+1);
                  }
              }
              if (n > 1) {
                  pf.put(1L, n);
                  //total*=2;
              }
              return pf;
          }
  
          static long upper_Bound(long a[], long x) {
              long l = -1, r = a.length;
              while (l + 1 < r) {
                  long m = (l + r) >>> 1;
                  if (a[(int) m] <= x)
                      l = m;
                  else
                      r = m;
              }
              return l + 1;
          }
  
          static int lower_Bound(ArrayList<Long> a, long x) {
              int l = 0, r = a.size()-1,ans=-1,mid=0;
              while(l<=r)
              {
                  mid=(l+r)>>1;
                  if(a.get(mid)<=x)
                  {
                      ans=mid;
                      l=mid+1;
                  }
                  else
                  {
                      r=mid-1;
                  }
              }
              return ans;
          }
  
          static int lower_Bound(int a[],int x) {
              int l = -1, r = a.length;
              while (l + 1 < r) {
                  int m = (l + r) >>> 1;
                  if (a[(int) m] >= x)
                      r = m;
                  else
                      l = m;
              }
              return r;
          }
  
          static int upperBound(int a[], int x) {// x is the key or target value
              int l=-1,r=a.length;
              while(l+1<r) {
                  int m=(l+r)>>>1;
                  if(a[m]<=x) l=m;
                  else r=m;
              }
              return l+1;
          }
  
          static int bsh(int  a[],int t) {
              int ans =-1;
              int i = 0, j = a.length - 1;
              while (i <= j) {
                  int mid = i + (j - i) / 2;
                  if (a[mid] > t) {
                      ans = mid;
                      //System.out.print("uppr "+a[ans]);
                      j=mid-1;
                  }
                  else{
                      //System.out.print("less "+a[mid]);
                      i=mid+1;
                  }
              }
              return ans;
          }
  
          static int bsl(int a[],int t) {
              int ans =-1;
              int i = 0, j = a.length-1;
              while (i <= j) {
                  int mid = i + (j - i) / 2;
                  if (a[mid] <= t) {
                      ans = mid;
                      i=mid+1;
                  } else if (a[mid] > t) {
                      j = mid - 1;
                  }
              }
              return ans;
          }
  
          static int upper_Bound(ArrayList<Long> a, long x)  //closest to the right
          {
              int l = 0, r = a.size()-1,ans=-1,mid=0;
              while(l<=r)
              {
                  mid=(l+r)>>1;
                  if(a.get(mid)>=x)
                  {
                      ans=mid;
                      r=mid-1;
                  }
                  else
                  {
                      l=mid+1;
                  }
              }
              return ans;
          }
  
          static boolean isSquarefactor(int x, int factor, int target) {
              int s = (int) Math.round(Math.sqrt(x));
              return factor * s * s == target;
          }
  
          static boolean isSquare(int x) {
              int s = (int) Math.round(Math.sqrt(x));
              return x * x == s;
          }
  
          static void sort(int a[]) // heap sort
          {
              PriorityQueue<Integer> q = new PriorityQueue<>();
              for (int i = 0; i < a.length; i++)
                  q.add(a[i]);
              for (int i = 0; i < a.length; i++)
                  a[i] = q.poll();
          }
  
          static void shuffle(int[] in) {
              for (int i = 0; i < in.length; i++) {
                  int idx = (int) (Math.random() * in.length);
                  fast_swap(in, idx, i);
              }
          }
  
          static boolean isPalindrome(String s)
          {
              StringBuilder sb=new StringBuilder(s);
              sb.reverse();
              if(s.equals(sb.toString()))
              {
                  return true;
              }
              return false;
          }
  
          static int[] computeLps(String pat) {
              int len = 0, i = 1, m = pat.length();
              int lps[] = new int[m];
              lps[0] = 0;
              while (i < m) {
                  if (pat.charAt(i) == pat.charAt(len)) {
                      ++len;
                      lps[i] = len;
                      ++i;
                  } else {
                      if (len != 0) {
                          len = lps[len - 1];
                      } else {
                          lps[i] = len;
                          ++i;
                      }
                  }
              }
              return lps;
          }
  
          static void kmp(String s, String pat,int[] prf,int[] st) {
              int n = s.length(), m = pat.length();
              int lps[] = computeLps(pat);
              int i = 0, j = 0;
              while (i < n) {
                  if (s.charAt(i) == pat.charAt(j)) {
                      i++;
                      j++;
                      if (j == m) {
                          ++prf[(i-j)+m];
                          ++st[(i-j)+1];
                          j=lps[j - 1];
                      }
  
                  } else {
                      if (j != 0) {
                          j = lps[j - 1];
                      } else {
                          i++;
                      }
                  }
              }
          }
  
          static void reverse_ruffle_sort(int a[]) {
              shuffle(a);
              Arrays.sort(a);
              for (int l = 0, r = a.length - 1; l < r; ++l, --r)
                  fast_swap(a, l, r);
  
          }
  
          static void ruffle_sort(int a[]) {
              shuffle(a);
              Arrays.sort(a);
          }
  
          static int getMax(int arr[], int n) {
              int mx = arr[0];
              for (int i = 1; i < n; i++)
                  if (arr[i] > mx)
                      mx = arr[i];
              return mx;
          }
  
          static ArrayList<Long> primeFactors(long n) {
              ArrayList<Long> al = new ArrayList<>();
              al.add(1L);
              while (n % 2 == 0) {
                  if(!al.contains(2L))
                  {
                      al.add(2L);
                  }
                  n /= 2L;
              }
  
              for (int i = 3; (long) i * i <= n; i += 2) {
                  while ((n % i == 0)) {
                      if(!al.contains((long)i))
                      {
                          al.add((long) i);
                      }
                      n /= i;
                  }
              }
  
              if (n > 2) {
                  if(!al.contains(n))
                  {
                      al.add(n);
                  }
              }
              return al;
          }
  
          static int[] z_function(String s) {
              int n = s.length(), z[] = new int[n];
  
              for (int i = 1, l = 0, r = 0; i < n; ++i) {
                  if (i <= r)
                      z[i] = Math.min(z[i - l], r - i + 1);
  
                  while (i + z[i] < n && s.charAt(z[i]) == s.charAt(i + z[i]))
                      ++z[i];
  
                  if (i + z[i] - 1 > r) {
                      l = i;
                      r = i + z[i] - 1;
                  }
              }
              return z;
          }
  
          static void swap(int a[], int idx1, int idx2) {
              a[idx1] += a[idx2];
              a[idx2] = a[idx1] - a[idx2];
              a[idx1] -= a[idx2];
          }
  
          static void fast_swap(int[] a, int idx1, int idx2) {
              if (a[idx1] == a[idx2])
                  return;
  
              a[idx1] ^= a[idx2];
              a[idx2] ^= a[idx1];
              a[idx1] ^= a[idx2];
          }
  
          public static void fast_sort(long[] array) {
              ArrayList<Long> copy = new ArrayList<>();
              for (long i : array)
                  copy.add(i);
              Collections.sort(copy);
              for (int i = 0; i < array.length; i++)
                  array[i] = copy.get(i);
          }
  
          static int divCount(int n) {
              boolean hash[] = new boolean[n + 1];
              Arrays.fill(hash, true);
              for (int p = 2; p * p < n; p++)
                  if (hash[p] == true)
                      for (int i = p * 2; i < n; i += p)
                          hash[i] = false;
  
              int total = 1;
              for (int p = 2; p <= n; p++) {
                  if (hash[p]) {
                      int count = 0;
                      if (n % p == 0) {
                          while (n % p == 0) {
                              n = n / p;
                              count++;
                          }
                          total = total * (count + 1);
                      }
                  }
              }
              return total;
          }
  
          static long binomialCoeff(long n,long k)
          {
              long res = 1;
  
              // Since C(n, k) = C(n, n-k)
              if (k > n - k)
                  k = n - k;
  
              // Calculate value of
              // [n * (n-1) *---* (n-k+1)] / [k * (k-1) *----* 1]
              for (int i = 0; i < k; ++i) {
                  res = (res*(n - i));
                  res /= (i + 1);
              }
              return res;
          }
  
          static long c(long fact[],long n,long k)
          {
              if(k>n) return 0;
              long res=fact[(int)n];
              res= (int) ((res * Modular_Expo(fact[(int)k], mod - 2))%mod);
              res= (int) ((res * Modular_Expo(fact[(int)n - (int)k], mod - 2))%mod);
              return res%mod;
          }
  
          public static ArrayList<Long> getFactors(long x) {
  
              ArrayList<Long> facts=new ArrayList<>();
              for(long i=2;i*i<=x;++i)
              {
                  if(x%i==0)
                  {
                      facts.add(i);
                      if(i!=x/i)
                      {
                          facts.add(x/i);
                      }
                  }
              }
              return facts;
          }
  
          public static HashMap<Integer, Integer> sortMap(HashMap<Integer, Integer> map) {
  
              List<Map.Entry<Integer,Integer>> list=new LinkedList<>(map.entrySet());
  
              Collections.sort(list,(o1,o2)->o2.getValue()-o1.getValue());
  
              HashMap<Integer,Integer> temp=new LinkedHashMap<>();
  
              for(Map.Entry<Integer,Integer> i:list)
              {
                  temp.put(i.getKey(),i.getValue());
              }
              return temp;
          }
  
          public static long lcm(long l,long l2) {
  
              long val=CP.gcd(l,l2);
              return (l*l2)/val;
  
          }
  
      }
  
  
      static void py() {
          System.out.println("YES");
      }
  
      static void pn() {
          System.out.println("NO");
      }
  
      static class OutputWriter {
          private final PrintWriter writer;
  
          public OutputWriter(OutputStream outputStream) {
              writer = new PrintWriter(new BufferedWriter(new OutputStreamWriter(outputStream)));
          }
  
          public OutputWriter(Writer writer) {
              this.writer = new PrintWriter(writer);
          }
  
          public void print(int[] array) {
              for (int i = 0; i < array.length; i++) {
                  if (i != 0) {
                      writer.print(' ');
                  }
                  writer.print(array[i]);
              }
          }
  
          public void printLine(int[] array) {
              print(array);
              writer.println();
          }
  
          public void close() {
              writer.close();
          }
  
          public void printLine(long i) {
              writer.println(i);
          }
  
          public void printLine(int i) {
              writer.println(i);
          }
          public void printLine(char c)
          {
              writer.println(c);
          }
  
          public void print(Object... objects) {
              for (int i = 0; i < objects.length; i++) {
                  if (i != 0) {
                      writer.print(' ');
                  }
                  writer.print(objects[i]);
              }
          }
  
          public void printLine(Object... objects) {
              print(objects);
              writer.println();
          }
      }
  }
  
  
  
  
  