#include<iostream>
#include<vector>

using namespace std;

const int INF = 1000000000;

int main(){
    int n, s, f;
    cin >> n >> s >> f;
    --s; --f;
    vector< vector< pair<int, int> > > g(n);
    for(int i = 0; i < n; ++i){
        for(int j = 0; j < n; ++j){
            int k;
            cin >> k;
            if(k != -1 && i != j)
                g[i].push_back(make_pair(j, k));
        }
    }
    vector<int> d(n, INF), p(n);
    d[s] = 0;
    vector<bool> u(n, false);
    for(int i = 0; i < n; ++i){
        int v = -1;
        for(int j = 0; j < n; ++j){
            if(!u[j] && (v == -1 || d[j] < d[v]))
                v = j;
        }
        if(d[v] == INF)
            break;
        u[v] = true;
        for(int j = 0; j < g[v].size(); ++j){
            int to = g[v][j].first;
            if (d[v] + g[v][j].second < d[to]) {
                d[to] = d[v] + g[v][j].second;
                p[to] = v;
            }
        }
    }
    if(d[f] == INF){
        cout << -1;
        return 0;
    }
    cout << d[f];
}