func_code_string: #include <bits/stdc++.h>   using namespace std;   int main() {     int t;     cin >> t;     while (t--) {       int n;       cin >> n;       char arr[n][n];       for (int i = 0; i < n; i++) {         for (int j = 0; j < n; j++) {           cin >> arr[i][j];         }       }       vector<pair<int, int>> vec;       if (arr[0][1] == arr[1][0]) {         if (arr[0][1] ==  1 ) {           if (arr[n - 2][n - 1] !=  0 ) {             vec.push_back({n - 1, n});           }           if (arr[n - 1][n - 2] !=  0 ) {             vec.push_back({n, n - 1});           }         } else {           if (arr[0][1] ==  0 ) {             if (arr[n - 2][n - 1] !=  1 ) {               vec.push_back({n - 1, n});             }             if (arr[n - 1][n - 2] !=  1 ) {               vec.push_back({n, n - 1});             }           }         }       } else if (arr[n - 1][n - 2] == arr[n - 2][n - 1]) {         if (arr[n - 1][n - 2] ==  1 ) {           if (arr[0][1] !=  0 ) {             vec.push_back({1, 2});           }           if (arr[1][0] !=  0 ) {             vec.push_back({2, 1});           }         } else {           if (arr[n - 1][n - 2] ==  0 ) {             if (arr[1][0] !=  1 ) {               vec.push_back({2, 1});             }             if (arr[0][1] !=  1 ) {               vec.push_back({1, 2});             }           }         }       } else {         if (arr[n - 1][n - 2] !=  1 ) {           vec.push_back({n, n - 1});         }         if (arr[n - 2][n - 1] !=  1 ) {           vec.push_back({n - 1, n});         }         if (arr[0][1] !=  0 ) {           vec.push_back({1, 2});         }         if (arr[1][0] !=  0 ) {           vec.push_back({2, 1});         }       }       cout << vec.size() << endl;       for (auto x : vec) {         cout << x.first <<     << x.second << endl;       }     }   }   