#include <bits/stdc++.h>
#define INF 1e9

using namespace std;

int g[111][111] , M[111] , d[111];
priority_queue<pair <int , int> , vector<pair<int , int> >, greater<pair <int , int> >> q;
int main() {
    int n , s , f;
    cin >> n >> s >> f;
    for (int i = 1; i <= n; i++) {
        for (int j = 1; j <= n; j++) {
            cin >> g[i][j];
            if (g[i][j] == -1) {
                g[i][j] = INF;
            }
        }
    }
    for (int i = 1; i <= n; i++) {
        d[i] = g[s][i];
        if (!(s == i)) q.push({d[i] , i});
    }
    M[s] = 1;
    for (int i = 2; i <= n; i++) {
        while (M[q.top().second] == 1) {
            if (q.empty()) {
                break;
            }
            q.pop();
        }
        int mn = q.top().first , v = q.top().second;
        M[v] = 1;
        for (int j = 1; j <= n; j++) {
            if (M[j] == 0 && d[j] > d[v] + g[v][j]) {
                d[j] = d[v] + g[v][j];
                q.push({d[j] , j});
            }
        }
    }
    if (d[f] != INF) {
        cout << d[f];
    } else {
        cout << -1;
    }
}