func_code_string: #include <bits/stdc++.h>   using namespace std;   bool a[55][55], b[55][55], ans[55][55];   int n, m, ans_cnt;   int main() {     cin >> n >> m;     for (int i = 1; i <= n; i++)       for (int j = 1; j <= m; j++) cin >> a[i][j];     for (int i = 1; i <= n - 1; i++)       for (int j = 1; j <= m - 1; j++)         if (a[i][j] && a[i + 1][j] && a[i][j + 1] && a[i + 1][j + 1]) {           ans[i][j] = true;           ans_cnt++;           b[i][j] = b[i + 1][j] = b[i][j + 1] = b[i + 1][j + 1] = true;         }     for (int i = 1; i <= n; i++)       for (int j = 1; j <= m; j++)         if (a[i][j] != b[i][j]) {           cout << -1;           return 0;         }     cout << ans_cnt <<   n ;     for (int i = 1; i <= n; i++)       for (int j = 1; j <= m; j++)         if (ans[i][j]) cout << i <<     << j <<   n ;     return 0;   }   