#include <iostream>

using namespace std;

const int MAXN = 10;
const int MAXM = 10;

int N, M;
int A[MAXN], B[MAXM];
int dp[MAXM + 1][1 << MAXN];

int main() {
	cin >> N;
	for (int i = 0; i < N; i++) {
		cin >> A[i];
	}
	cin >> M;
	for (int i = 0; i < M; i++) {
		cin >> B[i];
	}
	for (int i = 0; i < 1 << N; i++) {
		dp[0][i] = M + 1;
	}
	dp[0][0] = 0;
	for (int i = 0; i < M; i++) {
		for (int j = 0; j < 1 << N; j++) {
			dp[i + 1][j] = dp[i][j];
			int comb = j;
			while (comb != 0) {
				int sw = 0;
				for (int k = 0; k < N; k++) {
					if (((comb >> k) & 1) == 1) {
						sw += A[k];
					}
				}
				if (B[i] >= sw) {
					dp[i + 1][j] = min(dp[i + 1][j], dp[i][j ^ comb] + 1);
				}
				comb = j & (comb - 1);
			}
		}
	}
	if (dp[M][(1 << N) - 1] <= M) {
		cout << dp[M][(1 << N) - 1] << endl;
	} else {
		cout << -1 << endl;
	}
	return 0;
}