from collections import deque
import sys
input = sys.stdin.readline
N, M = map(int, input().split())
G = [[] for _ in range(N)]
for _ in range(M):
    u, v = map(int, input().split())
    u-=1
    v-=1
    G[u].append(v)
    G[v].append(u)
K = int(input())
if K>0:
    A = set(map(int, input().split()))
else:
    A = set()
deq = deque()
deq.append((0, 0))
INF = 10**9
dp = [[INF for _ in range(5)] for _ in range(N)]
dp[0][0] = 0
while deq:
    v, c = deq.popleft()
    for nv in G[v]:
        if nv+1 in A:
            nc = c+1
        else:
            nc = 0
        if nc==5:
            continue
        if dp[nv][nc]>dp[v][c]+1:
            dp[nv][nc] = dp[v][c]+1
            deq.append((nv, nc))
ans = min(dp[N-1])
if ans==INF:
    print(-1)
else:
    print(ans)