#include<iostream>
#include<fstream>

using namespace std;

int main() {
    ifstream fin("pathmgep.in");
    ofstream gaw("pathmgep.out");
    long n, i, j, k, s, f, v;
    fin >> n >> s >> f;
    long Matrix[n][n];
    long d[n][n];
    for (i = 0; i < n; i++) {
        for (j = 0; j < n; j++) {
            fin >> Matrix[i][j];
            if (Matrix[i][j] == -1)  Matrix[i][j] = 2000000000;
            d[i][j] = Matrix[i][j];
        }
    }
    for (i = 1; i < n + 1; i++){
        for (j = 0; j < n; j++){
            for (k = 0; k < n; k++){
                if (d[j][k] > d[j][i - 1] + d[i - 1][k]) d[j][k] = d[j][i - 1] + d[i - 1][k];
            }
        }
    }
    if (d[s - 1][f - 1] == 2000000000) d[s - 1][f - 1] = -1;
    gaw << d[s - 1][f - 1] << endl;
    fin.close();
}