#include <iostream>
#include <cstdlib>
#include <cstdio>
#include <vector>
#include <algorithm>

using namespace std;

const int MAX = 2005;
const long long INF = 9223372036854775807;

int n, m, start, finish, v;
long long w[MAX][MAX], d[MAX];
bool used[MAX];

void initialize(){
    for(int i = 0; i < n; i++)
        d[i] = INF;
}

int nextVertex(){
    int minV = -1;
    for(int i = 0; i < n; i++)
        if(!used[i] && (minV == -1 || d[i] < d[minV]))
            minV = i;

    return minV;
}

void dijkstra(int s){

    initialize();
    d[start] = 0;

    while((v = nextVertex()) != -1){
        used[v] = true;

        for(int i = 0; i < n; i++){
            long e = w[v][i];

            if(e == -1 || i == v)
                continue;

            if(d[i] > d[v] + e)
                d[i] = d[v] + e;

        }
    }
}

int main()
{
    freopen ("pathmgep.in", "r", stdin);
    freopen ("pathmgep.out" ,"w", stdout);

    scanf("%d%d%d", &n, &start, &finish);
    start--, finish--;

    for(int i = 0; i < n; i++)
        for(int j = 0; j < n; j++)
            scanf("%d", &w[i][j]);

    dijkstra(start);

    if(d[finish] == INF)
        cout << "-1" << endl;
    else
        cout << d[finish] << endl;;

    return 0;
}