from collections import defaultdict
import sys
input = sys.stdin.buffer.readline
sys.setrecursionlimit(10 ** 7)

N, M = map(int, input().split())
A = tuple(map(int, input().split()))
d = defaultdict(list)
for i, a in enumerate(A):
    d[a].append(i)

G = [[] for _ in range(N)]
for _ in range(M):
    a, b = map(int, input().split())
    a -= 1
    b -= 1
    G[a].append(b)
    G[b].append(a)

K = int(input())
ON = [0] * N
for b in map(int, input().split()):
    ON[b - 1] = 1

NG = [0] * N
ans = []
for a in sorted(set(A)):
    for i in d[a]:
        NG[i] = 1
    for s in d[a]:
        if not ON[s]:
            continue
        ans.append(s+1)
        for t in G[s]:
            if NG[t]:
                continue
            ON[t] ^= 1
print(len(ans))
print(*ans, sep="\n")