from collections import deque

n,m=map(int,input().split())
s,g=map(int,input().split())
G=[[] for i in range(n)]
for i in range(m):
   a,b=map(int,input().split()) 
   G[a-1].append(b-1)
   G[b-1].append(a-1)

u=input()
A=list(map(int,input().split()))

seen=[False]*n
deq=deque([])

deq.append(s-1)
seen[s-1]=True

for x in A:
    seen[x-1]="NG"

while len(deq):
    v=deq.popleft()
    for v2 in G[v]:
        if seen[v2] or seen[v2]=="NG":
            continue
        deq.append(v2)
        seen[v2]=True
        
if seen[g-1]:
    print("Yes")

else:
    print("No")