#include <bits/stdc++.h>
#define rep(i, n) for (int i = 0; i < (n); ++i)
using namespace std;
using ll = long long;

int main() {
    ll N;
    cin >> N;
    vector<int> rowSum, rowDiv, columnSum, columnDiv;
    rep(i, N) {
        int T;
        cin >> T;
        if (T == 1) {
            rowSum.push_back(i);
        }
        if (T == 2) {
            rowDiv.push_back(i);
        }
    }
    rep(i, N) {
        int T;
        cin >> T;
        if (T == 1) {
            columnSum.push_back(i);
        }
        if (T == 2) {
            columnDiv.push_back(i);
        }
    }

    ll ans = N * (rowDiv.size() + columnDiv.size()) - (rowDiv.size() * columnDiv.size());

    if (rowDiv.size() == 0 && columnDiv.size() == 0) {
        ans += max(columnSum.size(), rowSum.size());
    } else if (rowDiv.size() == 0) {
        ans += columnSum.size();
    } else if (columnDiv.size() == 0) {
        ans += rowSum.size();
    }
    cout << ans << endl;

    return 0;
}