n, m = map(int, input().split())
a = list(map(lambda x:[int(x), 0], input().split()))
g = [[] for _ in range(n)]
for i in range(m):
    u, v = map(int, input().split())
    u -= 1
    v -= 1
    if a[u] > a[v]:
        g[v].append(u)
    elif a[v] > a[u]:
        g[u].append(v)
for i in range(n):
    a[i][1] = i
k = int(input())
b = list(map(int, input().split()))
t = [0] * n
for i in range(k):
    t[b[i] - 1] = 1
a.sort()
res = []
for x, i in a:
    if t[i] == 1:
        res.append(i + 1)
        for node in g[i]:
            t[node] ^= 1
print(len(res))
for x in res:
    print(x)