from collections import Counter
N = int(input())
A = list(map(int, input().split()))
B = list(map(int, input().split()))

ca = Counter(A)
cb = Counter(B)

ans = N * (ca[2] + cb[2]) - ca[2] * cb[2]
if ca[2] % 2 == 1:
    cb[0], cb[1] = cb[1], cb[0]
if cb[2] % 2 == 1:
    ca[0], ca[1] = ca[1], ca[0]


while ca[1] and cb[1]:
    ans += 1
    ca[1] -= 1
    cb[1] -= 1

cnt = min(ca[1], cb[1])
ans += cnt
ans += ca[1] - cnt
ans += cb[1] - cnt
print(ans)