func_code_string: #include <bits/stdc++.h>   using namespace std;   const int N = 5e3 + 5;   int n, a[N][N];   char s[N];   bool vis[N];   void dfs(int x, int fa) {     vis[x] = 1;     for (int i = 1; i <= n; i++) {       if (!a[x][i] || i == fa || i == x) continue;       if (a[i][fa]) printf( %d %d %d n , x, i, fa), exit(0);       if (!vis[i]) dfs(i, x);     }   }   signed main() {     scanf( %d , &n);     for (int i = 1; i <= n; i++) {       scanf( %s , s + 1);       for (int j = 1; j <= n; j++) a[i][j] = s[j] -  0 ;     }     for (int i = 1; i <= n; i++)       if (!vis[i]) dfs(i, 0);     puts( -1 );     return 0;   }   