#include<bits/stdc++.h>
using namespace std;
int main() {
    int m;
    cin >> m;
    vector<int> a(m);
    for (int i = 0; i < m; ++i) {
        cin >> a[i];
    }
    sort(a.begin(), a.end());

    int n;
    cin >> n;
    vector<int> b(n);
    for (int i = 0; i < n; ++i) {
        cin >> b[i];
    }
    sort(b.begin(), b.end());

    int cnt = 0;
    int i = 0, j = 0;
    while (i < m && j < n) {
        if (a[i] >= b[j]) {
            cnt++;
            a[i] -= b[j];
            j++;
            if (a[i] == 0) {
                i++;
            }
        } else {
            i++;
        }
    }

    cout << cnt;
    return 0;
}