#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(B.begin(), B.end(), greater<int>());
	vector<int> a(1 << N);
	for (int S = 0; S < (1 << N); S++)
		for (int i = 0; i < N; i++)
			if (S & (1 << i)) a[S] += A[i];
	vector<int> dp(1 << N, INT_MAX / 2);
	dp[0] = 0;
	for (int S = 0; S < (1 << N); S++) {
		int T = S;
		do {
			if (dp[T] < M && a[S ^ T] <= B[dp[T]])
				dp[S] = min(dp[S], dp[T] + 1);
			T = (T - 1) & S;
		} while (T != S);
	}
	cout << (dp[(1 << N) - 1] < INT_MAX / 2 ? dp[(1 << N) - 1] : -1) << endl;
}