#include <bits/stdc++.h>   using namespace std;   bool pd[5005][5005];   char str[5005];   int n;   bool vis[5050];   bool dfs(int u, int lst) {     vis[u] = 1;     for (int i = 1; i <= n; ++i) {       if (!pd[u][i]) continue;       if (lst != -1 && pd[i][lst]) {         printf( %d %d %d n , lst, u, i);         return 1;       }       if (!vis[i] && dfs(i, u)) return 1;     }     return 0;   }   int main() {     scanf( %d , &n);     for (int i = 1; i <= n; ++i) {       scanf( %s , str + 1);       for (int j = 1; j <= n; ++j)         if (str[j] ==  1 ) pd[i][j] = 1;     }     for (int i = 1; i <= n; ++i)       if (!vis[i] && dfs(i, -1)) {         return 0;       }     printf( -1 n );     return 0;   }   