text: #include <iostream>
  
  using namespace std;
  
  int main()
  {
      int N, i, t;
      string A, B, out;
  
      cin >> N;   // Número de casos
      while(N--)
      {
          cin >> A >> B;
          i = 0;
          out = "";
  
          (A.size() < B.size()) ? t = A.size() : t = B.size();
  
          while(i != t)
          {
              out.push_back(A[i]);
              out.push_back(B[i++]);
          }
  
          if(A.size() < B.size())
              A = B;
  
          while(i != A.size())
              out.push_back(A[i++]);
  
          cout << out << endl;
      }
  
      return 0;
  }