#include <iostream>
#include <string>
#include <vector>
using namespace std;
int c[5000], pi[5000], a[3], n;
string graph[5000];
vector<int> res;

bool DFS(int v){
    c[v]=1;
    bool flag=false;
    for(int i=0;i<n;i++)
        if(graph[v][i]=='1' && c[i]==0){
            pi[i]=v;
            flag=flag || DFS(i);
        } else if(graph[v][i]=='1' && c[i]==1){
            if(pi[v]!=-1 && pi[pi[v]]!=-1 && pi[pi[v]]==i){
                res.push_back(i);
                res.push_back(pi[v]);
                res.push_back(v);
                return true;
            }
        }
        return flag;
}

int main()
{
    cin>>n;
    for(int i=0;i<n;i++){
        cin>>graph[i];
        c[i]=0;
        pi[i]=0;
    }
    if(DFS(0))
        cout<<res[0]+1<<' '<<res[1]+1<<' '<<res[2]+1;
    else
        cout<<-1;
    return 0;
}