//Dijkstra's Algo | https://informatics.mccme.ru/mod/statements/view3.php?id=193&chapterid=5#1
//Made by @maximihajlov | PhTS2020a | 1-Jun-2019

import java.util.Scanner;

public class Dijkstra {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);

        int INF = Integer.MAX_VALUE / 2;


        int N = sc.nextInt();
        int S = sc.nextInt()-1;
        int F = sc.nextInt()-1;

        int[][] m = new int[N][N];
        for (int i = 0; i < N; i++)
            for (int j = 0; j < N; j++) {
                m[i][j] = sc.nextInt();
                if(m[i][j]==-1)m[i][j]=INF;
            }

        boolean[] used = new boolean[N];
        int[] dist = new int[N];
        for (int i = 0; i < N; i++) dist[i] = INF;
        dist[S] = 0;

        while (true) {
            int v = -1;
            for (int i = 0; i < N; i++)
                if (!used[i] && dist[i] < INF && (v == -1 || dist[v] > dist[i]))
                    v = i;
            if (v == -1) break;
            used[v] = true;
            for (int i = 0; i < N; i++)
                if (!used[i] && m[v][i] < INF)
                    dist[i] = Math.min(dist[i], dist[v] + m[v][i]);

        }
        if(dist[F]<INF)System.out.println(dist[F]);
        else System.out.println(-1);
    }
}