from collections import deque, defaultdict

INF = 1 << 60
N, M = map(int, input().split())
adj = defaultdict(list)
for _ in range(M):
    U, V = map(lambda x: int(x)-1, input().split())
    adj[U].append(V)
    adj[V].append(U)


K = int(input())
if K > 0:
    iwis = set(list(map(lambda x: int(x)-1, input().split())))
else:
    iwis = set()

dists = [[INF] * 5 for _ in range(N)]
dists[0][0] = 0
q = deque([(0, 0)])
while q:
    v, c = q.popleft()
    if v == N-1:
        print(dists[v][c])
        break

    for to in adj[v]:
        nc = 0
        if to in iwis:
            nc = c + 1

        if nc == 5: continue
        if dists[to][nc] > dists[v][c] + 1:
            dists[to][nc] = dists[v][c] + 1
            q.append((to, nc))

else:
    print(-1)