N, M = map(int, input().split())
An = list(map(int, input().split()))
UV = [list(map(int, input().split())) for _ in range(M)]
K = int(input())
Bn = list(map(int, input().split()))

An_s = []
for i, A in enumerate(An, 1):
    An_s.append((A, i))
An_s.sort()
graph = [[] for _ in range(N+1)]
for U, V in UV:
    graph[U].append(V)
    graph[V].append(U)

light = [False] * (N+1)
for B in Bn:
    light[B] = True
ans = []
for v, i in An_s:
    if not light[i]:
        continue
    ans.append(i)
    light[i] = not light[i]
    for g in graph[i]:
        if An[g-1] <= v:
            continue
        light[g] = not light[g]

print(len(ans))
print(*ans, sep='\n')