import sys
from collections import *
from functools import cache, partial
from itertools import *
from pprint import pprint
from typing import Any, Final

try:
    from icecream import ic
except ImportError:  # Graceful fallback if IceCream isn't installed.
    ic = lambda *a: None if not a else (a[0] if len(a) == 1 else a)  # noqa
debug = partial(print, file=sys.stderr)
dpprint = partial(pprint, stream=sys.stderr)
sys.setrecursionlimit(10 ** 6)
MOD=998244353

N, M = map(int, input().split())
G: list[list[int]] = [[] 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()
else:
    A = list(map(int, input().split()))
    A = set([a - 1 for a in A])

# dp[i][j] := 頂点 i に来るまでに連続 A に属しているノードを j 個通ったときの最短距離
INF = float("inf")
X = 5
dp = [[INF] * (X + 1) for _ in range(N)]
dp[0][0] = 0

queue = deque([])
for v in G[0]:
    if v in A:
        ni = 1
    else:
        ni = 0
    dp[v][ni] = 1
    queue.append((v, ni))

while queue:
    u, i = queue.popleft()
    d = dp[u][i]
    for v in G[u]:
        if u in A and v in A:
            ni = i + 1
        elif v in A:
            ni = 1
        else:
            ni = 0
        if ni >= X:
            continue
        nd = d + 1
        if dp[v][ni] == INF:
            dp[v][ni] = nd
            queue.append((v, ni))

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