#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;

void update(pair<int,int>& a, pair<int, int> b){
    if(b.first < a.first){
        a = b;
    } else if(b.first == a.first && b.second > a.second){
        a = b;
    }
}

int main(){
    int N, M;
    
    cin >> N;
    vector<int> A(N);
    for(int i=0;i<N;i++)cin >> A[i];
    
    cin >> M;
    vector<int> B(M);
    for(int i=0;i<M;i++)cin >> B[i];
    
    sort(B.rbegin(), B.rend());
    
    const pair<int,int> none = make_pair(1000, -1);;
    vector< pair<int,int> > dp(1 << N, none);
    
    dp[0] = make_pair(0, B[0]);
    for(int S=0;S<1<<N;S++){
        if(dp[S] == none)continue;
        
        int k = dp[S].first;
        int rest = dp[S].second;
        
        for(int i=0;i<N;i++){
            if((S >> i) & 1)continue;
            if(A[i] > rest)continue;
            
            update(dp[S | (1 << i)], make_pair(k, rest - A[i]));
        }
        
        if(k + 1 < M){
            for(int i=0;i<N;i++){
                if((S >> i) & 1)continue;
                if(A[i] > B[k + 1])continue;
                
                update(dp[S | (1 << i)], make_pair(k + 1, B[k + 1] - A[i]));
            }
        }
    }
    
    int res = -1;
    if(dp[(1 << N) - 1] != none){
        res = dp[(1 << N) - 1].first + 1;
    }
    
    cout << res << endl;
    return 0;
}