description: You are given strings S and T, consisting of lowercase English letters. It is guaranteed that T is a permutation of the string abc. 
  
  Find string S', the lexicographically smallest permutation of S such that T is not a subsequence of S'.
  
  String a is a permutation of string b if the number of occurrences of each distinct character is the same in both strings.
  
  A string a is a subsequence of a string b if a can be obtained from b by deletion of several (possibly, zero or all) elements.
  
  A string a is lexicographically smaller than a string b if and only if one of the following holds:
  
    * a is a prefix of b, but a ≠ b;
    * in the first position where a and b differ, the string a has a letter that appears earlier in the alphabet than the corresponding letter in b.
  
  Input
  
  Each test contains multiple test cases. The first line contains a single integer t (1 ≤ t ≤ 1000) — the number of test cases. Description of the test cases follows.
  
  The first line of each test case contains a string S (1 ≤ |S| ≤ 100), consisting of lowercase English letters.
  
  The second line of each test case contains a string T that is a permutation of the string abc. (Hence, |T| = 3).
  
  Note that there is no limit on the sum of |S| across all test cases.
  
  Output
  
  For each test case, output a single string S', the lexicographically smallest permutation of S such that T is not a subsequence of S'.
  
  Example
  
  Input
  
  
  7
  abacaba
  abc
  cccba
  acb
  dbsic
  bac
  abracadabra
  abc
  dddddddddddd
  cba
  bbc
  abc
  ac
  abc
  
  
  Output
  
  
  aaaacbb
  abccc
  bcdis
  aaaaacbbdrr
  dddddddddddd
  bbc
  ac
  
  Note
  
  In the first test case, both aaaabbc and aaaabcb are lexicographically smaller than aaaacbb, but they contain abc as a subsequence.
  
  In the second test case, abccc is the smallest permutation of cccba and does not contain acb as a subsequence.
  
  In the third test case, bcdis is the smallest permutation of dbsic and does not contain bac as a subsequence.
solution: import java.io.*;
  import java.util.Arrays;
  import java.util.*;
  import java.util.Scanner;
  import java.util.StringTokenizer;
  
  
  
  
  public class copy {
  
  
      public static boolean checker(long[] arr, long K, long diff) {
          long collect = 0;
          for (int i = 0; i < arr.length; i++) {
              if (arr[i] > diff)
                  collect += arr[i] - diff;
          }
  
          if (collect >= K)
              return true;
          else
              return false;
      }
  
      public static long search(long[] arr, long K, long R) {
          long l = 0;
          long r = R;
  
          while (l <= r) {
              long mid = (l + r) / 2;
  
              if (checker(arr, K, mid)) {
                  if (checker(arr, K, mid + 1))
                      l = mid + 1;
                  else
                      return mid;
              } else
                  r = mid - 1;
          }
          return -1;
      }
  
      static void sieveOfEratosthenes(int n, ArrayList<Integer> arr, ArrayList<Integer> arr1) {
          // Create a boolean array
          // "prime[0..n]" and
          // initialize all entries
          // it as true. A value in
          // prime[i] will finally be
          // false if i is Not a
          // prime, else true.
          boolean prime[] = new boolean[n + 1];
          for (int i = 0; i <= n; i++)
              prime[i] = true;
  
          for (int p = 2; p * p <= n; p++) {
              // If prime[p] is not changed, then it is a
              // prime
              if (prime[p] == true) {
  
                  // Update all multiples of p
                  for (int i = p * p; i <= n; i += p)
                      prime[i] = false;
              }
          }
  
          // Print all prime numbers
          int x = 0;
          for (int i = 2; i <= n; i++) {
              if (prime[i] == true) {
  
                  arr.add(i);
  
  
              }
  
          }
          System.out.println(arr.size());
      }
  
      public static boolean check(String s, int K, char ch) {
          ArrayList<Integer> arr = new ArrayList<>();
          for (int i = 0; i < s.length(); i++) {
              if (s.charAt(i) == ch)
                  arr.add(i);
          }
  //        if(K==1 && ch=='z')
  //            System.out.println(arr);
          if (arr.size() == 0)
              return false;
          if (arr.get(0) >= K)
              return false;
          if (s.length() - 1 - arr.get(arr.size() - 1) >= K)
              return false;
          for (int i = 1; i < arr.size(); i++) {
              if (arr.get(i) - arr.get(i - 1) > K)
                  return false;
          }
          return true;
      }
  
      public static int check(long N) {
          int sum = 0;
          while (N > 0) {
              sum += N % 10;
              N = N / 10;
          }
          return sum;
  
      }
  
      public static long call(long N) {
          long l = 1;
          long r = (long) Math.floor(Math.sqrt(N));
          while (l <= r) {
              long mid = (l + r) / 2;
              double left = N / (double) (mid) - mid;
              int right = check(mid);
              System.out.println(mid + " " + left + " " + right);
              if (mid == 10)
                  System.out.println(left + " " + right);
              if (left > right)
                  l = mid + 1;
              else if (right > left)
                  r = mid - 1;
              else
                  return mid;
          }
          return -1;
      }
  
      public static int path(ArrayList<ArrayList<Integer>> arr, int X, int parent, int[] gold, PriorityQueue<Integer> pq) {
          int max = 0;
          ArrayList<Integer> ch = new ArrayList<>();
          for (int i : arr.get(X)) {
              if (i != parent) {
                  ch.add(path(arr, i, X, gold, pq));
              }
          }
          Collections.sort(ch, Collections.reverseOrder());
          for (int i = 1; i < ch.size(); i++)
              pq.add(ch.get(i));
  
  
          if (ch.size() == 0)
              return gold[X];
          else
              return ch.get(0) + gold[X];
  
      }
  
      public static long fac(long N, long mod) {
          if (N == 0)
              return 1;
          if(N==1)
              return 1;
          return ((N % mod) * (fac(N - 1, mod) % mod)) % mod;
      }
  
      public static String form(char ch, int freq) {
          String s = "";
          for (int i = 1; i <= freq; i++)
              s += ch;
          return s;
      }
  
      static long power(long x, long y, long p) {
  
          // Initialize result
          long res = 1;
  
          // Update x if it is more than or
          // equal to p
          x = x % p;
  
          while (y > 0) {
  
              // If y is odd, multiply x
              // with result
              if (y % 2 == 1)
                  res = (res * x) % p;
  
              // y must be even now
              y = y >> 1; // y = y/2
              x = (x * x) % p;
          }
  
          return res;
      }
  
      // Returns n^(-1) mod p
      static long modInverse(long n, long p) {
          return power(n, p - 2, p);
      }
  
      // Returns nCr % p using Fermat's
      // little theorem.
      static long nCrModPFermat(long n, long r,
                                long p) {
  
          if (n < r)
              return 0;
          // Base case
          if (r == 0)
              return 1;
  
          // Fill factorial array so that we
          // can find all factorial of r, n
          // and n-r
  
  
  //        System.out.println(modInverse(fac(r,p),p));
  //        System.out.println(modInverse(fac(n-r,p),p));
          return ((fac(n, p) % p * (modInverse(fac(r, p), p)
                  % p)) % p * (modInverse(fac(n - r, p), p)
                  % p)) % p;
      }
  
      public static boolean check(long[] arr, long time, int M) {
          long sum = 0;
          int count = 0;
          for (int i = 0; i < arr.length; i++) {
              sum += arr[i];
              if (sum >= time) {
                  ++count;
                  sum = 0;
              }
          }
  
          if (sum >= time)
              ++count;
  
          return count >= M;
      }
  
      public static int check(ArrayList<Integer> arr, ArrayList<Integer> arr2) {
          int l = 0, r = 0, ans = 0;
          while (l < arr.size() && r < arr2.size()) {
              if (arr.get(l) < arr2.get(r))
                  ++l;
              else if (arr.get(l) > arr2.get(r))
                  ++r;
              else {
                  ++ans;
                  ++l;
                  ++r;
              }
          }
          return ans;
      }
  
  
      public static int find(int[] parent, int x) {
          if (parent[x] == x)
              return x;
          return find(parent, parent[x]);
      }
  
      public static int merge(int[] parent, int[] rank, int x, int y,int[] child) {
          int x1 = find(parent, x);
          int y1 = find(parent, y);
          int c=0;
          if (rank[x1] > rank[y1]) {
              parent[y1] = x1;
              child[x1]+=child[y1];
              c=child[x1];
  
          } else if (rank[y1] > rank[x1]) {
              parent[x1] = y1;
              child[y1]+=child[x1];
              c=child[y1];
          } else {
              parent[y1] = x1;
              rank[x1]++;
              child[x1]+=child[y1];
              c=child[x1];
          }
  
          return c;
      }
  
      public static int bfs(ArrayList<ArrayList<Integer>> arr, int e1, int e2, int N) {
          boolean[] visited = new boolean[N];
          visited[0] = true;
          int[] dist = new int[N];
          Queue<Integer> queue = new LinkedList<>();
          queue.add(0);
          Arrays.fill(dist, -1);
          dist[0] = 0;
          while (queue.size() > 0) {
              int x = queue.poll();
              for (int i : arr.get(x)) {
                  if (!visited[i] || (e1 == x && e2 == i)) {
                      System.out.println(x + " " + dist[x]);
                      dist[i] = dist[x] + 1;
                      visited[i] = true;
                      queue.add(i);
                  }
              }
  
          }
  
  
          return dist[N - 1];
      }
  
  
  
  
  
  
  
  
      public static int binarysearch(ArrayList<Integer> possible, int X, int start) {
          int l = start, r = possible.size() - 1;
  
          while (l <= r) {
              int mid = (l + r) / 2;
              if (possible.get(mid) > X) {
                  if (mid - 1 >= start && possible.get(mid - 1) > X)
                      r = mid - 1;
                  else
                      return mid;
              } else
                  l = mid + 1;
          }
  
          return -1;
      }
  
  
  
  
  
  
  
      public static long gcd(long a, long b) {
          if (b == 0)
              return a;
  
          return gcd(b, a % b);
      }
  
  
      public static void leftRotatebyOne(int arr[], int n) {
          int i, temp;
          temp = arr[0];
          for (i = 0; i < n - 1; i++)
              arr[i] = arr[i + 1];
          arr[n - 1] = temp;
      }
  
  
  
      static int power(int x, int y, int p)
      {
  
          // Initialize result
          int res = 1;
  
          // Update x if it is more than or
          // equal to p
          x = x % p;
  
          while (y > 0) {
  
              // If y is odd, multiply x
              // with result
              if (y % 2 == 1)
                  res = (res * x) % p;
  
              // y must be even now
              y = y >> 1; // y = y/2
              x = (x * x) % p;
          }
  
          return res;
      }
  
      // Returns n^(-1) mod p
      static int modInverse(int n, int p)
      {
          return power(n, p - 2, p);
      }
  
      // Returns nCr % p using Fermat's
      // little theorem.
      static int nCrModPFermat(int n, int r,
                               int p)
      {
  
          if (n<r)
              return 0;
          // Base case
          if (r == 0)
              return 1;
  
          // Fill factorial array so that we
          // can find all factorial of r, n
          // and n-r
          int[] fac = new int[n + 1];
          fac[0] = 1;
  
          for (int i = 1; i <= n; i++)
              fac[i] = fac[i - 1] * i % p;
  
          return (fac[n] * modInverse(fac[r], p)
                  % p * modInverse(fac[n - r], p)
                  % p)
                  % p;
      }
  
  
  
      public static long[][] ncr(int n,int r)
      {
          long[][] dp=new long[n+1][r+1];
          for(int i=0;i<=n;i++)
              dp[i][0]=1;
          for(int i=1;i<=n;i++)
          {
              for(int j=1;j<=r;j++)
              {
                  if(j>i)
                      continue;
                  dp[i][j]=dp[i-1][j-1]+dp[i-1][j];
              }
          }
  
          return dp;
  
      }
  
      static boolean status=false;
      static int x1=-1,y1=-1;
      public static int dfs(ArrayList<ArrayList<Integer>> arr,int X,int[] ans,int value,int parent)
      {
          int xor=ans[X];
          for(int i:arr.get(X))
          {
              if(i!=parent)
              {
                  int x=dfs(arr,i,ans,value,X);
                  if(x==-1)
                      return -1;
                  if(x==value)
                  {
                      x1=X;
                      y1=i;
                      return -1;
                  }
                  xor=xor^x;
              }
          }
  
  
  
          return xor;
      }
  
      public static boolean prime(long N)
      {
          int c=0;
          for(int i=2;i*i<=N;i++)
          {
              if(N%i==0)
                  ++c;
          }
  
          return c==0;
      }
      static int[] c;
      static boolean sta=true;
      public static int dfs(ArrayList<ArrayList<Integer>> arr,int N,int j,int[] status,boolean[] visited)
      {
          Queue<Integer> queue=new LinkedList<>();
          queue.add(j);
          status[j]=1;
          visited[j]=true;
          int[] color=new int[2];
          while(queue.size()>0)
          {
              int temp=queue.poll();
              if(temp<N)
                  color[status[temp]]++;
              for(int i:arr.get(temp))
              {
                  if(visited[i])
                  {
                      if(status[i]==status[temp])
                          return -1;
                  }
                  else
                  {
                      queue.add(i);
                      status[i]=1-status[temp];
                      visited[i]=true;
                  }
              }
          }
  
          return Math.max(color[0],color[1]);
      }
  
      public static boolean check(String s,int N,long D,long C,long M)
      {
          int index=s.lastIndexOf('D');
          for(int i=0;i<=index;i++)
          {
              if(s.charAt(i)=='D' && D>0)
              {
                  D-=1;
                  C+=M;
              }
              else if(s.charAt(i)=='C' && C>0)
              {
                  C-=1;
              }
              else
                  return false;
          }
  
          return true;
      }
  
  
  
  
      public static boolean checkbounds(int x,int y,int N,int M)
      {
          return x>=0 && x<N && y>=0 && y<M;
      }
  
      public static void dfs(int x,int y,char[][] grid,boolean[][] visited,int N,int M)
      {
          visited[x][y]=true;
          if(checkbounds(x+1,y,N,M) && !visited[x+1][y] && grid[x+1][y]=='.')
              dfs(x+1,y,grid,visited,N,M);
          if(checkbounds(x-1,y,N,M) && !visited[x-1][y] && grid[x-1][y]=='.')
              dfs(x-1,y,grid,visited,N,M);
          if(checkbounds(x,y+1,N,M) && !visited[x][y+1] && grid[x][y+1]=='.')
              dfs(x,y+1,grid,visited,N,M);
          if(checkbounds(x,y-1,N,M) && !visited[x][y-1] && grid[x][y-1]=='.')
              dfs(x,y-1,grid,visited,N,M);
      }
  
      public static int bin(ArrayList<Integer> arr,int search)
      {
          int l=0,r=arr.size()-1;
          if(search<arr.get(0))
              return -1;
          if(search>arr.get(r-1))
              return r+1;
          while(l<=r)
          {
              int mid=(l+r)/2;
              if(arr.get(mid)>search)
              {
                  if(mid-1>=0 && arr.get(mid-1)>search)
                      r=mid-1;
                  else
                      return mid;
              }
              else
                  l=mid+1;
          }
  
          return -1;
      }
  
  
      public static int mcbc(ArrayList<Long> arr,long search,int N,int lower)
      {
          if(search>=arr.get(N))
              return N;
  
          if(search<=arr.get(lower))
              return lower;
          int l=lower;
          int r=N;
          while(l<=r)
          {
              int mid=(l+r)/2;
              if(arr.get(mid)==search)
              {
                  return mid;
              }
  
              if(arr.get(mid)>search)
              {
                  if(mid-1>=lower && arr.get(mid-1)>=search)
                      r=mid-1;
                  else
                  {
                      if(mid-1>=lower)
                      {
                          if (Math.abs(search - arr.get(mid)) < Math.abs(search - arr.get(mid - 1)))
                              return mid;
                          else
                              return mid - 1;
                      }
                      else
                          return mid;
                  }
              }
  
              else if(arr.get(mid)<search)
              {
                  if(mid+1<=N && arr.get(mid+1)<=search)
                      l=mid+1;
                  else
                  {
                      if(mid+1<=N)
                      {
                          if (Math.abs(search - arr.get(mid)) < Math.abs(search - arr.get(mid + 1)))
                              return mid;
                          else
                              return mid + 1;
                      }
                      else
                          return mid;
                  }
              }
          }
  
          return -1;
  
      }
  
      public static int check(String s,char ch)
      {
          int l=0,r=s.length()-1;
          int c=0;
          while(l<r)
          {
              if(s.charAt(l)!=s.charAt(r))
              {
                  if(s.charAt(l)==ch)
                  {
                      ++c;
                      ++l;
                  }
                  else if(s.charAt(r)==ch)
                  {
                      ++c;
                      --r;
                  }
                  else
                  {
                      return -1;
                  }
              }
              else
              {
                  ++l;
                  --r;
              }
          }
  
          return c;
  
      }
  
  
  
      static boolean cycle=false;
  
      public static void check(int x1,int y1,String[][] s,boolean[][] visited,int N,int M,int[] xdiff,int[] ydiff,div[][] ans,int index)
      {
          Queue<div> queue1=new LinkedList<>();
          Queue<div> queue2=new LinkedList<>();
          visited[x1][y1]=true;
          queue1.add(new div(x1,y1));
          queue2.add(new div(x1,y1));
          int c=0;
          while(queue1.size()>0)
          {
              div temp=queue1.poll();
              //System.out.println("hello");
              int x=temp.x;
              int y=temp.y;
              ++c;
              for(int i=0;i<4;i++)
              {
                  if(getbounds(x+xdiff[i],y+ydiff[i],N,M))
                  {
                      if(!visited[x+xdiff[i]][y+ydiff[i]] && s[x+xdiff[i]][y+ydiff[i]].equals("."))
                      {
                          queue1.add(new div(x+xdiff[i],y+ydiff[i]));
                          queue2.add(new div(x+xdiff[i],y+ydiff[i]));
                          visited[x+xdiff[i]][y+ydiff[i]]=true;
                      }
                  }
              }
          }
  
          div com=new div(index,c);
  
          while(queue2.size()>0)
          {
  
              div temp=queue2.poll();
              int x=temp.x;
              int y=temp.y;
              ans[x][y]=com;
          }
  
      }
  
      static int connected=0;
  
      public static int edges(ArrayList<ArrayList<Integer>> arr,int x,boolean[] visited)
      {
          ++connected;
          int sum=arr.get(x).size();
          visited[x]=true;
          for(int i:arr.get(x))
          {
              if(!visited[i])
                  sum+=edges(arr,i,visited);
          }
  
          return sum;
  
      }
  
  
  
  
  
      public static boolean getbounds(int x,int y,int N,int M)
      {
          return x>=0 && x<N && y>=0 && y<M;
      }
  
      public static boolean drag(long h,ArrayList<Integer> interval,long mid)
      {
          long ans=0;
          for(int i=1;i<interval.size();i++)
          {
              ans+=Math.min(mid,interval.get(i)-interval.get(i-1));
          }
          ans+=mid;
          return ans>=h;
      }
  
  
      public static long search(ArrayList<Integer> interval,long h)
      {
          long l=1;long r=(long)Math.pow(10,18);
          while(l<=r)
          {
              long mid=(l+r)/2;
              if(drag(h,interval,mid))
              {
                  if(mid-1>=1 && drag(h,interval,mid-1))
                      r=mid-1;
                  else
                      return mid;
              }
              else
                  l=mid+1;
          }
  
          return -1;
  
      }
  
  
  
  
  
  
  
  
      public static void main(String[] args) throws IOException {
          Reader.init(System.in);
          BufferedWriter output = new BufferedWriter(new OutputStreamWriter(System.out));
          int T = Reader.nextInt();
          A:for (int m = 1; m <= T; m++) {
  
              String s = Reader.next();
  
              String t = Reader.next();
              String ans = "";
              HashMap<Character, Integer> hp = new HashMap<>();
              for (char ch = 0; ch < s.length(); ch++)
                  hp.put(s.charAt(ch), hp.getOrDefault(s.charAt(ch), 0) + 1);
              if (!hp.containsKey('a') || !hp.containsKey('b') || !hp.containsKey('c')) {
                  for (char ch = 'a'; ch <= 'z'; ch++) {
                      for (int j = 1; j <= hp.getOrDefault(ch, 0); j++)
                          ans += ch;
  
                  }
                  output.write(ans + "\n");
                  continue A;
              }
                  String check = "a";
                  if (t.charAt(1) == 'b' && t.charAt(0) == 'a')
                      check += "cb";
                  else
                      check += "bc";
  
                  for (int i = 0; i < 3; i++) {
                      for (int j = 1; j <= hp.getOrDefault(check.charAt(i), 0); j++)
                          ans += check.charAt(i);
                  }
  
                  for (char ch = 'd'; ch <= 'z'; ch++) {
                      for (int j = 1; j <= hp.getOrDefault(ch, 0); j++)
                          ans += ch;
  
  
                  }
  
                  output.write(ans + "\n");
  
  
  
  
  
  
  
          }
          output.flush();
      }
  }
  
  
  
  class Reader {
      static BufferedReader reader;
      static StringTokenizer tokenizer;
  
      static void init(InputStream input) {
          reader = new BufferedReader(
                  new InputStreamReader(input));
          tokenizer = new StringTokenizer("");
      }
  
      static String next() throws IOException {
          while (!tokenizer.hasMoreTokens()) {
              tokenizer = new StringTokenizer(
                      reader.readLine());
          }
          return tokenizer.nextToken();
      }
  
      static int nextInt() throws IOException {
          return Integer.parseInt(next());
      }
  
      static long nextLong() throws IOException {
          return Long.parseLong(next());
      }
  
      static double nextDouble() throws IOException {
          return Double.parseDouble(next());
      }
  }
  
  
  class sortat implements Comparator<div>
  {
      public int compare(div o1,div o2)
      {
          return o1.x-o2.x;
      }
  }
  
  class div {
      int x, y;
  
      div(int x1,int z1) {
          x = x1;
          y=z1;
  
      }
  }
  
  class TreeNode
  {
      int data;
      TreeNode left;
      TreeNode right;
      TreeNode(int data)
      {
          left=null;
          right=null;
          this.data=data;
      }
  }