import sys

# sys.setrecursionlimit(10**6)
int1 = lambda x: int(x)-1
p2D = lambda x: print(*x, sep="\n")
def II(): return int(sys.stdin.buffer.readline())
def FI(): return float(sys.stdin.buffer.readline())
def LI(): return list(map(int, sys.stdin.buffer.readline().split()))
def LI1(): return list(map(int1, sys.stdin.buffer.readline().split()))
def LLI(rows_number): return [LI() for _ in range(rows_number)]
def LLI1(rows_number): return [LI1() for _ in range(rows_number)]
def BI(): return sys.stdin.buffer.readline().rstrip()
def SI(): return sys.stdin.buffer.readline().rstrip().decode()
# dij = [(0, 1), (-1, 0), (0, -1), (1, 0)]
# dij = [(0, 1), (-1, 0), (0, -1), (1, 0), (1, 1), (1, -1), (-1, 1), (-1, -1)]
dij = [(0, 1), (1, 0), (1, 1), (1, -1)]
inf = 10**16
md = 998244353
# md = 10**9+7

n, m = LI()
aa = LI()
to = [[] for _ in range(n)]
for _ in range(m):
    u, v = LI1()
    if aa[u] == aa[v]: continue
    if aa[u] > aa[v]: u, v = v, u
    to[u].append(v)

topo = []
fin = [False]*n
def dfs(u):
    fin[u] = True
    for v in to[u]:
        if fin[v]: continue
        dfs(v)
    topo.append(u)

for u in range(n):
    if fin[u]: continue
    dfs(u)

k = II()
bb = LI1()
dp = [False]*n
for b in bb: dp[b] = True

ans = []
for u in topo[::-1]:
    if dp[u]:
        ans.append(u+1)
        for v in to[u]:
            dp[v] = not dp[v]

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