from collections import defaultdict, deque

n, m = map(int, input().split())
s, g = map(int, input().split())
edge = defaultdict(list)
for _ in range(m):
    f, t = map(int, input().split())
    edge[f].append(t)
    edge[t].append(f)
_ = int(input())
seen = set(map(int, input().split()))
seen.add(s)

Que = deque([s])
while Que:
    curr = Que.popleft()
    if curr == g:
        print("Yes")
        exit()
    for np in edge[curr]:
        if np in seen:
            continue
        seen.add(np)
        Que.append(np)
print("No")