#include <iostream>
#include <cstdio>
#include <vector>
#include <algorithm>
#include <functional>
#include <cstring>
using namespace std;
#define SORT(x) sort((x).begin(), (x).end())
#define RSORT(x) sort((x).begin(), (x).end(), greater<int>() )
#define CLEAR(d) memset((d), 0, (sizeof((d))))

int main()
{
    int n, m, ans = 0, g = 0;
    cin >> n;
    vector<int> a(n);
    for (int i = 0; i < n; i++) {
        cin >> a[i];
    }
    cin >> m;
    vector<int> b(m);
    for (int i = 0; i < m; i++) {
        cin >> b[i];
    }
    RSORT(a);
    RSORT(b);
    int t[10];
    CLEAR(t);
    for (ans = 0; ans < m; ans++) {
        int sum = b[ans];
        for (int i = 0; i < n; i++) {
            if (t[i] == 0 && sum >= a[i]) {
                sum -= a[i];
                t[i] = 1;
            }
        }
        int flag = 0;
        for (int i = 0; i < n; i++) {
            if (t[i] == 0) {
                flag = 1;
                break;
            }
        }
        if (flag == 0) {
            g = 1;
            break;
        }
    }
    if (g == 0) ans = -2;
    printf("%d\n", ans+1);
    return 0;
}