n,m = map(int,input().split())
g = [[] for _ in range(n)]
for _ in range(m):
    u,v = map(lambda x:int(x)-1,input().split())
    g[u].append(v)
    g[v].append(u)
k = int(input())
iwai = [False] * n

if k > 0:
    a = list(map(lambda x:int(x)-1,input().split()))
    for v in a:
        iwai[v] = True

from collections import deque,defaultdict,Counter

def bfs(v):
    visited = [[False] * 5 for _ in range(n)]
    dq = deque([(v, 0, 0)])
    while dq:
        v, c, d = dq.popleft()
        if v == n-1:
            exit(print(d))
        if visited[v][c]:
            continue
        visited[v][c] = True
        for nv in g[v]:
            if not iwai[nv]:
                dq.append((nv, 0, d+1))
            else:
                if c+1 < 5:
                    dq.append((nv, c+1, d+1))
bfs(0)
print(-1)