ABA ABA

#include <iostream>
#include <queue>
using namespace std;

int n, x, y;
vector<int> g[105];
bool cond;
int d[105];
bool vis[105];
queue<int> q;

void into_new(int order)
{
    q.push(order);
    vis[order] = true;
}

void bfs() {
    into_new(x);
    while (!q.empty()) {
        int now = q.front();
        q.pop();
        if (now == y) return;
        for (int neighbour : g[now]) {
            if (vis[neighbour]) continue;
            else {
                into_new(neighbour);
                d[neighbour] = d[now] + 1;
            }
        }
    }
}

int main() {
    cin >> n >> x >> y;
    for (int i = 1; i <= n; i++) {
        for (int j = 1; j <= n; j++) {
            cin >> cond;
            if (cond) {
                g[i].push_back(j);
            }
        }
    }
    bfs();
    cout << d[y] - 1 << endl;
    return 0;
}