from collections import deque

n, m = map(int, input().split())
g = [[] 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())
is_yiwiy9 = [False] * n
if k != 0:
    a = list(map(int, input().split()))
    for a_i in a:
        is_yiwiy9[a_i - 1] = True

vis = [[-1] * n for _ in range(5)]
que = deque()
vis[0][0] = 0
que.append((0, 0))
while que:
    ct, ci = que.popleft()
    if ci == n - 1:
        print(vis[ct][ci])
        exit()

    for ni in g[ci]:
        nt = ct + 1 if is_yiwiy9[ni] else 0
        if nt == 5:
            continue
        if vis[nt][ni] == -1:
            vis[nt][ni] = vis[ct][ci] + 1
            que.append((nt, ni))

print(-1)