import os,io,heapq
input=io.BytesIO(os.read(0,os.fstat(0).st_size)).readline
n,m=map(int,input().split())
a=list(map(int,input().split()))
graph=[]
for i in range(n):
  graph.append([])
for i in range(m):
  c,d=map(int,input().split())
  graph[c-1].append(d-1)
  graph[d-1].append(c-1)
k=int(input())
b=list(map(int,input().split()))
queue=[]
for i in range(n):
  queue.append((a[i],i+1))
queue.sort()
ans=[]
lights=[0]*n
for i in range(k):
  lights[b[i]-1]=1
for i in range(n):
  val,pos=queue[i]
  if lights[pos-1]==1:
    ans.append(pos)
    for j in graph[pos-1]:
      if a[j]>val:
        lights[j]=1-lights[j]
print(len(ans))
for i in ans:
  print(i)