import collections

N, M = map(int, input().split())
links = [[] for _ in range(N)]
for _ in range(M):
    u, v = map(int, input().split())
    u -= 1
    v -= 1
    links[u].append(v)
    links[v].append(u)

A = [False] * N
K = int(input())
if K > 0:
    T = list(map(int, input().split()))
    for t in T:
        A[t-1] = True

inf = 10**18
visited = [[inf]*5 for _ in range(N)]
visited[0][0] = 0
que = collections.deque([(0, 0)])
while que:
    x, p = que.popleft()
    for nx in links[x]:
        if A[nx]:
            np = p + 1
        else:
            np = 0
            
        if np >= 5:
            continue
        
        if visited[nx][np] != inf:
            continue
        
        visited[nx][np] = visited[x][p] + 1
        que.append((nx, np))



ans = min(visited[N-1])
if ans == inf:
    ans = -1

print(ans)