func_code_string: #include <bits/stdc++.h>   using namespace std;   int main() {     ios_base::sync_with_stdio(false);     cin.tie(NULL);     cout.tie(NULL);     int t = 1;     cin >> t;     while (t--) {       int n, m, i, x = 0, y, z;       cin >> n;       string s[n + 1];       for (int i = 0; i < n; i++) cin >> s[i];       vector<pair<int, int>> v;       if (s[0][1] == s[1][0]) {         if (s[n - 1][n - 2] == s[0][1]) {           v.push_back({n, n - 1});         }         if (s[n - 2][n - 1] == s[0][1]) {           v.push_back({n - 1, n});         }       } else if (s[n - 1][n - 2] == s[n - 2][n - 1]) {         if (s[n - 1][n - 2] == s[0][1]) {           v.push_back({1, 2});         }         if (s[n - 2][n - 1] == s[1][0]) {           v.push_back({2, 1});         }       } else {         if (s[0][1] !=  0 ) {           v.push_back({1, 2});         }         if (s[1][0] !=  0 ) {           v.push_back({2, 1});         }         if (s[n - 2][n - 1] !=  1 ) {           v.push_back({n - 1, n});         }         if (s[n - 1][n - 2] !=  1 ) {           v.push_back({n, n - 1});         }       }       cout << v.size() << endl;       for (int i = 0; i < v.size(); i++) {         cout << v[i].first <<     << v[i].second << endl;       }     }     return 0;   }   