import sys
input = sys.stdin.buffer.readline

from collections import deque

N, M = map(int, input().split())

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

g = [[] for _ in range(N)]
deg = [0] * N

for _ in range(M):
    u, v = map(int, input().split())
    u -= 1; v -= 1
    if A[u] < A[v]:
        g[u].append(v)
        deg[v] += 1
    elif A[u] > A[v]:
        g[v].append(u)
        deg[u] += 1

tps = sorted(range(N), key=lambda x: A[x])

K = int(input())
B = list(map(int, input().split()))

C = [0] * N

for b in B:
    C[b - 1] = 1

res = []

for v in tps:
    if C[v] == 1:
        for adj in g[v]:
            C[adj] ^= 1
        res.append(v + 1)

print(len(res))
print('\n'.join(map(str, res)))