from collections import deque

N,M=map(int,input().split())

E=[[] for i in range(N)]

for i in range(M):
    x,y=map(int,input().split())
    x-=1
    y-=1
    E[x].append(y)
    E[y].append(x)

K=int(input())
if K!=0:
    A=list(map(int,input().split()))

X=[0]*N
for a in A:
    X[a-1]=1

DP=[[1<<60]*N for i in range(6)]

DP[0][0]=0

Q=[(0,0)]
Q=deque(Q)

while Q:
    now,iwi=Q.popleft()

    for to in E[now]:
        if X[to]==0:
            if DP[0][to]>DP[iwi][now]+1:
                DP[0][to]=DP[iwi][now]+1
                Q.append((to,0))
        else:
            if iwi+1<5 and DP[iwi+1][to]>DP[iwi][now]+1:
                DP[iwi+1][to]=DP[iwi][now]+1
                Q.append((to,iwi+1))

ANS=1<<60
for i in range(6):
    ANS=min(ANS,DP[i][N-1])

if ANS==1<<60:
    print(-1)
else:
    print(ANS)