n,m=map(int,input().split())
a=[-1]+list(map(int,input().split()))
root=[[] for i in range(n+1)]
rootr=[[] for i in range(n+1)]
import sys
sys.setrecursionlimit(10**9)
for i in range(m):
    v,u=map(int,input().split())
    if a[v]>a[u]:
        root[u].append(v)
        rootr[v].append(u)
    elif a[u]>a[v]:
        root[v].append(u)
        rootr[u].append(v)
memo=[-1]*(n+1)
light=[0]*(n+1)
ans=[]
k=int(input())
b=list(map(int,input().split()))
for x in b:light[x]=1
def ch(x):
    light[x]^=1
    ans.append(x)
    for nod in root[x]:
        light[nod]^=1
def f(x):
    if memo[x]==1:pass
    for nod in rootr[x]:f(nod)
    if light[x]==1:ch(x)
    memo[x]=1
for i in range(1,n+1):f(i)
print(len(ans))
for x in ans:print(x)