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: 
  /*****  --->         :)    Vijender  Srivastava      (:       <---       *****/
  
  
  import java.util.*;
  import java.lang.*;
  import java.io.*;
  public class Main
  {
      static FastReader sc =new FastReader();
      static PrintWriter out=new PrintWriter(System.out);
      static int mod=10000007;
      /* start */
      public static void main(String [] args)
      {
          int t = i();
          while(t-->0)
          {
              int n = i();
              ArrayList<Integer> l = new ArrayList<Integer>();
              for(int i=0;i<n;i++)
              {
                  l.add(i());
              }
              Collections.sort(l);
              int cnt = 0;
              for(int i=1;i<l.size();i++)
              {
                  if(cnt==n/2) break;
  
                  System.out.println(l.get(i)+" "+l.get(0));
                  cnt++;
              }
          }
  
          out.close();
      }
  
      /* end */
      static class FastReader
      {
          BufferedReader br;
          StringTokenizer st;
  
          public FastReader()
          {
              br = new BufferedReader(new
                      InputStreamReader(System.in));
          }
  
          String next()
          {
              while (st == null || !st.hasMoreElements())
              {
                  try
                  {
                      st = new StringTokenizer(br.readLine());
                  }
                  catch (IOException  e)
                  {
                      e.printStackTrace();
                  }
              }
              return st.nextToken();
          }
  
          int nextInt()
          {
              return Integer.parseInt(next());
          }
  
          long nextLong()
          {
              return Long.parseLong(next());
          }
  
          double nextDouble()
          {
              return Double.parseDouble(next());
          }
  
          String nextLine()
          {
              String str = "";
              try
              {
                  str = br.readLine();
              }
              catch (IOException e)
              {
                  e.printStackTrace();
              }
              return str;
          }
      }
  
      static void p(Object o)
      {
          out.print(o);
      }
      static void pl(Object o)
      {
          out.println(o);
      }
      static int i() {
          return sc.nextInt();
      }
  
      static String s() {
          return sc.next();
      }
  
      static long l() {
          return sc.nextLong();
      }
  
      static char[] inputC()
      {
          String s = sc.nextLine();
          return s.toCharArray();
      }
  
      static int[] input(int n) {
          int A[]=new int[n];
          for(int i=0;i<n;i++) {
              A[i]=sc.nextInt();
          }
          return A;
      }
  
      static long[] inputL(int n) {
          long A[]=new long[n];
          for(int i=0;i<n;i++) {
              A[i]=sc.nextLong();
          }
          return A;
      }
  
      static long[] putL(long a[]) {
          long A[]=new long[a.length];
          for(int i=0;i<a.length;i++) {
              A[i]=a[i];
          }
          return A;
      }
  
      static String[] inputS(int n) {
          String A[]=new String[n];
          for(int i=0;i<n;i++) {
              A[i]=sc.next();
          }
          return A;
      }
  
      static int gcd(int a, int b)
      {
          if (a == 0)
              return b;
          return gcd(b % a, a);
      }
  
      static long gcd(long a, long b)
      {
          if (a == 0)
              return b;
          return gcd(b % a, a);
      }
  
      static int lcm(int a, int b)
      {
          return (a / gcd(a, b)) * b;
      }
  
      static String reverse(String s) {
          StringBuffer p=new StringBuffer(s);
          p.reverse();
          return p.toString();
      }
  
      static int min(int a,int b) {
          return Math.min(a, b);
      }
      static int min(int a,int b,int c) {
          return Math.min(a, Math.min(b, c));
      }
      static int min(int a,int b,int c,int d) {
          return Math.min(a, Math.min(b, Math.min(c, d)));
      }
  
      static int max(int a,int b) {
          return Math.max(a, b);
      }
      static int max(int a,int b,int c) {
          return Math.max(a, Math.max(b, c));
      }
      static int max(int a,int b,int c,int d) {
          return Math.max(a, Math.max(b, Math.max(c, d)));
      }
      static long min(long a,long b) {
          return Math.min(a, b);
      }
      static long min(long a,long b,long c) {
          return Math.min(a, Math.min(b, c));
      }
      static long min(long a,long b,long c,long d) {
          return Math.min(a, Math.min(b, Math.min(c, d)));
      }
      static long max(long a,long b) {
          return Math.max(a, b);
      }
      static long max(long a,long b,long c) {
          return Math.max(a, Math.max(b, c));
      }
      static long max(long a,long b,long c,long d) {
          return Math.max(a, Math.max(b, Math.max(c, d)));
      }
  
      static long sum(int A[]) {
          long sum=0;
          for(int i : A) {
              sum+=i;
          }
          return sum;
      }
  
      static long sum(long A[]) {
          long sum=0;
          for(long i : A) {
              sum+=i;
          }
          return sum;
      }
  
      static void print(int A[]) {
          for(int i : A) {
              System.out.print(i+" ");
          }
          System.out.println();
      }
  
      static void print(long A[]) {
          for(long i : A) {
              System.out.print(i+" ");
          }
          System.out.println();
      }
  
      static long mod(long x) {
          return ((x%mod + mod)%mod);
      }
  
      static long power(long x, long y)
      {
  
          if(y==0)
              return 1;
          if(x==0)
              return 0;
          long res = 1;
          while (y > 0) {
  
              if (y % 2 == 1)
                  res = (res * x) ;
  
              y = y >> 1;
              x = (x * x);
          }
  
          return res;
      }
  
      static boolean prime(int n)
      {
          if (n <= 1)
              return false;
          if (n <= 3)
              return true;
          if (n % 2 == 0 || n % 3 == 0)
              return false;
          double sq=Math.sqrt(n);
  
          for (int i = 5; i <= sq; i = i + 6)
              if (n % i == 0 || n % (i + 2) == 0)
                  return false;
          return true;
      }
  
      static boolean prime(long n)
      {
          if (n <= 1)
              return false;
          if (n <= 3)
              return true;
          if (n % 2 == 0 || n % 3 == 0)
              return false;
          double sq=Math.sqrt(n);
  
          for (int i = 5; i <= sq; i = i + 6)
              if (n % i == 0 || n % (i + 2) == 0)
                  return false;
          return true;
      }
      //pair class
      private static class Pair implements Comparable<Pair> {
          int first, second;
          public Pair(int f, int s) {
              first = f;
              second = s;
          }
          @Override
          public int compareTo(Pair p) {
              if (first > p.first)
                  return 1;
              else if (first < p.first)
                  return -1;
              else {
                  if (second > p.second)
                      return 1;
                  else if (second < p.second)
                      return -1;
                  else
                      return 0;
              }
          }
  
      }
  }
  