n, m = map(int, input().split()) A = list(map(int, input().split())) A2 = [(A[i], i) for i in range(n)] A2.sort() G = [[] for _ in range(n)] for _ in range(m): u, v = map(int, input().split()) G[u - 1].append(v - 1) G[v - 1].append(u - 1) k = int(input()) B = set(map(int, input().split())) onoff = [0] * n for i in B: onoff[i - 1] = 1 ans = [] for a, i in A2: if onoff[i]: ans.append(i + 1) onoff[i] ^= 1 for v in G[i]: if a < A[v]: onoff[v] ^= 1 print(len(ans)) print(*ans, sep="\n")