# 想定解法(1112134) をChatGPTで変換した
import sys
from collections import deque

def main():
    data = list(map(int, sys.stdin.buffer.read().split()))
    it = iter(data)

    N = next(it)
    M = next(it)

    edges = [[] for _ in range(N)]
    for _ in range(M):
        u = next(it) - 1
        v = next(it) - 1
        edges[u].append(v)
        edges[v].append(u)

    K = next(it)
    is_iwai = [False] * N
    for _ in range(K):
        A = next(it) - 1
        is_iwai[A] = True

    INF = 10**18
    # dists[i][j] := 岩井星人に連続でj回会ったうえで頂点iに到達するまでの最短距離
    dists = [[INF] * 5 for _ in range(N)]

    q = deque()
    q.append((0, 0))
    dists[0][0] = 0

    while q:
        now, iwai_cnt = q.popleft()
        nowd = dists[now][iwai_cnt]
        for nxt in edges[now]:
            next_iwai_cnt = iwai_cnt + 1 if is_iwai[nxt] else 0
            if next_iwai_cnt >= 5:
                continue
            if dists[nxt][next_iwai_cnt] <= nowd + 1:
                continue
            dists[nxt][next_iwai_cnt] = nowd + 1
            q.append((nxt, next_iwai_cnt))

    ans = dists[N - 1][0]
    print(-1 if ans == INF else ans)

if __name__ == "__main__":
    main()