from queue import Queue


def dijkstra(G):
    for i in range(len(matrix[G])):
        if matrix[G][i] >= 0:
            dist[i] = matrix[G][i]
            qeueu.put(i)
    dist[G] = 0
    while qeueu:
        first_el = qeueu.get()
        for i in range(len(matrix[first_el])):
            if matrix[first_el][i] > 0:
                if dist[i] > dist[first_el] + matrix[first_el][i]:
                    dist[i] = dist[first_el] + matrix[first_el][i]
                    qeueu.put(i)


N, S, F = map(int, input().split())
S -= 1
F -= 1
matrix = [list() for _ in range(N)]
for i in range(N):
    matrix[i] = list(map(int, input().split()))
dist = [10 ** 100] * N
used = [False] * N
qeueu = Queue()
dijkstra(S)
if dist[F] == 10 ** 100:
    print(-1)
else:
    print(dist[F])