#define _USE_MATH_DEFINES
#include <algorithm>
#include <cstdio>
#include <functional>
#include <iostream>
#include <cstring>
#include <climits>
#include <cmath>
#include <map>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <string>
#include <time.h>
#include <vector>
using namespace std;
 
typedef long long ll;
typedef unsigned long long ull;
typedef pair<int, int> i_i;
typedef pair<ll, int> ll_i;
typedef pair<double, int> d_i;
typedef pair<ll, ll> ll_ll;
typedef pair<double, double> d_d;
struct edge { int u, v; ll w; };
 
ll MOD = 1000000007;

int main() {
	int N; cin >> N;
	vector<int> A(N);
	for (int i = 0; i < N; i++) cin >> A[i];
	int M; cin >> M;
	vector<int> B(M);
	for (int j = 0; j < M; j++) cin >> B[j];
	sort(A.begin(), A.end());
	sort(B.begin(), B.end(), greater<int>());
	int ans = INT_MAX;
	do {
		vector<int> _B = B;
		int j = 0;
		bool flag = true;
		for (int i = 0; i < N; i++) {
			while (j < M && A[i] > _B[j]) j++;
			if (j == M) {
				flag = false;
				continue;
			}
			_B[j] -= A[i];
		}
		if (flag) ans = min(ans, j + 1);
	} while (next_permutation(A.begin(), A.end()));
	cout << (ans < INT_MAX ? ans : -1) << endl;
}