N,M = map(int, input().split())
edge = [[] for i in range(N)]
for i in range(M):
    u,v = map(int, input().split())
    u-=1;v-=1
    edge[u].append(v)
    edge[v].append(u)
#print(edge)

K = int(input())
if K > 0:
    A = list(map(int, input().split()))
check = [0] * N
for i in range(K):
    check[A[i]-1] = 1
dp = [[10**10]*5 for i in range(N)]

from collections import deque
que = deque([(0,0)])
dp[0][0] = 0

while que:
    dist,now = que.popleft()

    for _next in edge[now]:
        if check[_next] == 1:
            if dist+1 < 5:
                if dp[_next][dist+1] > dp[now][dist] + 1:
                    dp[_next][dist+1] = dp[now][dist] + 1
                    que.append((dist+1,_next))
        else:
            if dp[_next][0] > dp[now][dist] + 1:
                dp[_next][0] = dp[now][dist] + 1
                que.append((0,_next))
print(dp[-1][0] if dp[-1][0] != 10**10 else -1)