n,m=map(int, input().split())
G = [[] for i in range(n)]

for _ in range(m):
    a,b=map(lambda x: int(x) - 1, input().split())
    G[a].append(b)
    G[b].append(a)

k=int(input())
if k>0:
    A=set(map(lambda x: int(x) - 1, input().split()))
else:
    A=set()

seen=[[-1]*5 for i in range(n)]
seen[0][0]=0

from collections import deque
q = deque()
q.append((0, 0)) # 最初の頂点を入れておく

while q:
    cur_node, iwi_cnt = q.popleft()
    if cur_node==n-1:
        print(seen[cur_node][iwi_cnt])
        exit()

    for nxt_node in G[cur_node]:
        if nxt_node in A:
            nxt_cnt=iwi_cnt+1
            if nxt_cnt>=5:
                continue
        else:
            nxt_cnt=0
        
        if seen[nxt_node][nxt_cnt]==-1:
            seen[nxt_node][nxt_cnt]=seen[cur_node][iwi_cnt]+1
            q.append((nxt_node, nxt_cnt))
print(-1)