#include <iostream>
#include <cstdio>
#include <vector>
#include <algorithm>
#include <utility>

using namespace std;

const int INF = 1e9;

int main() {
	int n, m;
	vector<int> a, b;

	cin >> n;
	a.assign(n, 0);
	for (int i = 0; i < n; i++) {
		cin >> a[i];
	}

	cin >> m;
	b.assign(m, 0);
	for (int i = 0; i < m; i++) {
		cin >> b[i];
	}

	sort(a.begin(), a.end());
	sort(b.begin(), b.end(), greater<int>());
	b.push_back(INF);

	int min_idx = INF;
	int a_idx, b_idx, rest;
	do {
		a_idx = 0;
		b_idx = 0;
		rest = b[b_idx];

		while(a_idx < n) {
			if (a[a_idx] <= rest) {
				rest -= a[a_idx];
				a_idx++;
			} else {
				b_idx++;
				rest = b[b_idx];
			}
		}

		if (b_idx < m) {
			min_idx = min(min_idx, b_idx);
		}
	} while (next_permutation(a.begin(), a.end()));

	int ans = min_idx == INF ? -1 : min_idx + 1;
	cout << ans << endl;

	return 0;
}