from collections import deque, defaultdict, Counter
from bisect import bisect_left, bisect_right
from itertools import permutations, combinations
from heapq import heappop, heappush
import math, sys
# input = sys.stdin.readline
_int = lambda x: int(x)-1
MOD = 998244353 #10**9+7
INF = 1<<60
Yes, No = "Yes", "No"

N, M = map(int, input().split())
E = defaultdict(list)
for _ in range(M):
    u, v = map(_int, input().split())
    E[u].append(v)
    E[v].append(u)
iwai = [0]*N

K = int(input())
if K > 0:
    A = list(map(int, input().split()))
    for i in range(K): iwai[A[i]-1] = 1

vis = [[INF]*5 for _ in range(N)]

vis[0][0] = 0

q = deque([(0, 0)])
while q:
    i, k = q.popleft()
    if vis[i][k] == -1: continue
    for j in E[i]:
        if iwai[j]:
            if k == 4: continue
            if vis[j][k+1] != INF: continue
            vis[j][k+1] = vis[i][k]+1
            q.append((j, k+1))
        else:
            if vis[j][0] != INF: continue
            vis[j][0] = vis[i][k]+1
            q.append((j, 0))

ans = min(vis[N-1])
if ans == INF: ans = -1
print(ans)