n,m=map(int,input().split())
a=list(map(int,input().split()))
g=[[] for _ in range(n)]
for i in range(m):
    u,v=map(int,input().split())
    g[u-1].append(v-1)
    g[v-1].append(u-1)
k=int(input())
b=list(map(int,input().split()))

arr=[0]*n
for i in range(n):
    arr[i]=(i,a[i])
arr=sorted(arr,key=lambda x: x[1])

on=[0]*n
for j in range(k):
    on[b[j]-1]=1


ans=[]
for i in range(n):
    p=arr[i][0]
    if on[p]==0:
        continue
    for c in g[p]:
        if on[c]:
            if a[c]>a[p]:
                on[c]=0
    ans.append(p+1)
print(len(ans))
print(*ans,sep='\n')