N = int(input())
S = list(map(int,input().split()))
T = list(map(int,input().split()))
s2 = S.count(2)
t2 = T.count(2)
ssum = 0
tsum = 0
for s in S:
    if s==1:
        ssum+=max(1,t2)
    if s==2:
        ssum+=N
for t in T:
    if t==1:
        tsum+=max(1,s2)
    if t==2:
        tsum+=N
print(max(ssum,tsum))