def relax(u, v, l):
    dist[v] = min(dist[v], dist[u] + l)


def dijkstra(st, fin):
    global n
    global dist
    global used
    dist[st] = 0
    for i in range(n):
        v = -1
        d = 10 ** 19
        for j in range(n):
            if used[j] ==  -1 and dist[j] < d:
                d = dist[j]
                v = j
        if v == -1:
            break

        used[v] = 1
        for elem in gr[v]:
            relax(v, elem[0], elem[1])
    if used[fin] == -1:
        return -1
    else:
        return dist[fin]


n, st, fin = map(int, input().split())
st -= 1
fin -= 1
matrix = []
gr = [[] * n for i in range(n)]
for i in range(n):
    matrix.append(list(map(int, input().split())))
for i in range(len(matrix)):
    for j in range(len(matrix)):
        if i != j and matrix[i][j] != -1:
            gr[i].append((j, matrix[i][j]))
dist = [10 ** 19] * n
used = [-1] * n
print(dijkstra(st, fin))