ha-ha

#include <iostream>
#include <string>
#include <vector>
#include <algorithm>
#include <queue>
#include <queue>
#include <math.h>
using namespace std;
int arr[107][107],d[107],p[107];
bool used[107];
int main()
{
    int i,j,n,s,m;
    cin>>n;
    for (i=1; i<=n; ++i)
    {
        for (j=1; j<=n; ++j)
        {
            cin>>arr[i][j];
        }
    }
    cin>>s>>m;
    queue<int> q;
    q.push(s);
    vector<bool> used(n);
    used[s]=true;
    p[s]=-1;
    while (!q.empty())
    {
        int v=q.front();
        q.pop();
        for (i=1; i<=n; ++i)
        {
            int to = arr[v][i];
            if (to==1)
            {
                if (!used[i])
                {
                    used[i]=true;
                    q.push(i);
                    d[i]=d[v]+1;
                    p[i]=v;
                }
            }
        }

    }
    if (!used[m])
    {
        cout<<-1;
    }
    else
    {
        cout<<d[m]<<'\n';
        vector<int> path;
        for (int v=m; v!=-1; v=p[v])
            path.push_back(v);
        for (i=path.size()-1; i>=0; --i) cout<<path[i]<<" ";
    }
}