func_code_string: #include <bits/stdc++.h>   using namespace std;   signed main() {     ios_base::sync_with_stdio(false);     cin.tie(0);     cout.tie(0);     ;     long long T = 1;     cin >> T;     while (T--) {       long long n;       cin >> n;       char a[n][n];       for (long long i = 0; i < n; i++)         for (long long j = 0; j < n; j++) cin >> a[i][j];       vector<pair<long long, long long> > v;       if (a[1][0] ==  0  && a[0][1] ==  0 ) {         if (a[n - 1][n - 2] !=  1 ) v.push_back({n - 1, n - 2});         if (a[n - 2][n - 1] !=  1 ) v.push_back({n - 2, n - 1});       } else if (a[1][0] ==  0  && a[0][1] ==  1 ) {         if (a[n - 1][n - 2] ==  0  && a[n - 2][n - 1] ==  0 ) {           v.push_back({1, 0});         } else if (a[n - 1][n - 2] ==  1  && a[n - 2][n - 1] ==  0 ) {           v.push_back({n - 1, n - 2});           v.push_back({1, 0});         } else if (a[n - 1][n - 2] ==  0  && a[n - 2][n - 1] ==  1 ) {           v.push_back({n - 2, n - 1});           v.push_back({1, 0});         } else {           v.push_back({0, 1});         }       } else if (a[1][0] ==  1  && a[0][1] ==  1 ) {         if (a[n - 1][n - 2] !=  0 ) v.push_back({n - 1, n - 2});         if (a[n - 2][n - 1] !=  0 ) v.push_back({n - 2, n - 1});       } else if (a[1][0] ==  1  && a[0][1] ==  0 ) {         if (a[n - 1][n - 2] ==  0  && a[n - 2][n - 1] ==  0 ) {           v.push_back({0, 1});         } else if (a[n - 1][n - 2] ==  1  && a[n - 2][n - 1] ==  0 ) {           v.push_back({n - 1, n - 2});           v.push_back({0, 1});         } else if (a[n - 1][n - 2] ==  0  && a[n - 2][n - 1] ==  1 ) {           v.push_back({n - 2, n - 1});           v.push_back({0, 1});         } else {           v.push_back({1, 0});         }       }       cout << v.size() <<   n ;       for (auto it = (v).begin(); it != (v).end(); it++)         cout << it->first + 1 <<     << it->second + 1 <<   n ;     }     return 0;   }   