#include <stdio.h>

long long inf = 1000000000000LL;

long long m[52][52];

long long min(long long a, long long b)
{
    return a < b ? a : b;
}

int main()
{
    int i, j, k, n, from, to;
    scanf("%i %i %i", &n, &from, &to);
    for(i = 1; i <= n; ++i)
    {
        for(j = 1; j <= n; ++j)
        {
            scanf("%lli", &m[i][j]);
            if(m[i][j] == -1)
            {
                m[i][j] = inf;
            }
        }
    }
    for(k = 1; k <= n; ++k)
    {
        for(i = 1; i <= n; ++i)
        {
            for(j = 1; j <= n; ++j)
            {

                m[i][j] = min(m[i][j], m[i][k] + m[k][j]);
            }
        }
    }
    printf("%lli\n", m[from][to] == inf ? -1 : m[from][to]);
    return 0;
}