from collections import deque

n, m = map(int, input().split())

g = [[] for _ in range(n)]
inf = int(1e9)
for _ in range(m):
    u, v = map(int, input().split())
    u, v = u - 1, v - 1
    g[u].append(v)
    g[v].append(u)

k = int(input())
a = list(map(int, input().split())) if k else []
is_yiwiy = [0] * n
for v in a:
    is_yiwiy[v - 1] = 1
dp = [[inf] * 5 for _ in range(n)]
dp[0][0] = 0

q = deque([(0, 0)])
while q:
    x, c = q.popleft()

    for y in g[x]:
        nc = 0 if not is_yiwiy[y] else c + 1
        if nc >= 5:
            continue
        if dp[y][nc] != inf:
            continue
        dp[y][nc] = dp[x][c] + 1
        q.append((y, nc))

ans = min(dp[-1])
print(-1 if ans == inf else ans)