func_code_string: #include <bits/stdc++.h>   using namespace std;   int main() {     int n, i, j;     cin >> n;     set<int> row;     set<int> col;     map<int, int> row_map;     map<int, int> col_map;     for (i = 1; i <= n; i++) {       string s;       cin >> s;       for (j = 1; j <= n; j++) {         if (s[j - 1] ==  . ) {           row.insert(i);           col.insert(j);           row_map[i] = j;           col_map[j] = i;         }       }     }     if (row.size() == n) {       for (i = 1; i <= n; i++) {         cout << i <<     << row_map[i] << endl;       }     } else if (col.size() == n) {       for (j = 1; j <= n; j++) {         cout << col_map[j] <<     << j << endl;       }     } else       cout << -1 << endl;   }   