krsu 2234

/*
by: senb1
*/

#include <bits/stdc++.h>

#define ll long long
#define all(x) x.begin(), x.end()
#define fr first
#define sc second
#define mk make_pair
#define endl '\n'

using namespace std;

const ll inf = 1e9 + 6;
const ll maxn = 2e5 + 5;

void solve() {
    int n;
    cin >> n;
    vector<int> v(n), t(n);
    for (int i = 0; i < n; i++)
        cin >> v[i];

    int s = 0;
    multiset<int> st;
    for (int i = 0; i < n; i++) {
        cin >> t[i];
        if (t[i] == 1) {
            s += v[i];
        } else {
            if (s >= v[i]) {
                s -= v[i];
                st.insert(-v[i]);
            } else if (-*st.begin() > v[i]) {
                s += (-*st.begin() - v[i]);
                st.erase(st.begin());
                st.insert(-v[i]);
            }
        }
    }
    cout << st.size() << endl;
}
/*
7
5 8 9 3 2 7 9
1 1 2 2 2 1 2
*/

int main() {
    ios::sync_with_stdio(0);
    cin.tie(0);

    int t = 1;
    // cin >> t;
    while (t--)
        solve();
}