text: #include <cmath>
  #include <cstdio>
  #include <vector>
  #include <iostream>
  #include <algorithm>
  using namespace std;
  
  class Matrix {
    public:
      vector<vector<int>> a;
  };
  
  Matrix operator+(const Matrix& left, const Matrix& right) {
      Matrix ret;
      ret.a = vector<vector<int>>(left.a.size(), vector<int>(left.a[0].size()));
      for (int row = 0; row < left.a.size(); row++){
        for (int col = 0; col < left.a[row].size(); col++ ) {
          ret.a[row][col] = right.a[row][col] + left.a[row][col];
        }
      }
      return ret;
  }
  
  int main () {
     int cases,k;
     cin >> cases;
     for(k=0;k<cases;k++) {
        Matrix x;
        Matrix y;
        Matrix result;
        int n,m,i,j;
        cin >> n >> m;
        for(i=0;i<n;i++) {
           vector<int> b;
           int num;
           for(j=0;j<m;j++) {
              cin >> num;
              b.push_back(num);
           }
           x.a.push_back(b);
        }
        for(i=0;i<n;i++) {
           vector<int> b;
           int num;
           for(j=0;j<m;j++) {
              cin >> num;
              b.push_back(num);
           }
           y.a.push_back(b);
        }
        result = x+y;
        for(i=0;i<n;i++) {
           for(j=0;j<m;j++) {
              cout << result.a[i][j] << " ";
           }
           cout << endl;
        }
     }  
     return 0;
  }