#include <iostream>
#include <vector>
#include <cmath>
#include <map>
#include <set>
#include <iomanip>
#include <queue>
#include <algorithm>
#include <numeric>
#include <deque>
#include <complex>

using namespace std;

int main(){

    long long N, M, mx, s;
    cin >> N;
    vector<long long> A(N);
    for (int i=0; i<N; i++) cin >> A[i];
    mx = 1LL<<N;
    cin >> M;
    vector<long long> B(M), S(mx);
    for (int i=0; i<M; i++) cin >> B[i];
    for (int i=0; i<mx; i++){
        s = 0;
        for (int j=0; j<N; j++){
            if (i & 1<<j) s += A[j];
        }
        S[i] = s;
    }

    sort(B.begin(), B.end(), greater<long long>());

    vector<vector<bool>> dp(M+1, vector<bool>(mx));
    dp[0][0] = 1;

    for (int i=1; i<=M; i++){
        for (int k=0; k<mx; k++){
            if (S[k] > B[i-1]) continue;
            for (int j=0; j<mx; j++){
                if (j & k) continue;
                dp[i][j|k] = (dp[i][j|k] | dp[i-1][j]);
            }
        }
    }

    for (int i=0; i<=M; i++){
        if (dp[i][mx-1]){
            cout << i << endl;
            return 0;
        }
    }

    cout << -1 << endl;

    return 0;
}