#include <cstdio>
#include <iostream>
#include <sstream>
#include <fstream>
#include <iomanip>
#include <algorithm>
#include <cmath>
#include <string>
#include <vector>
#include <list>
#include <queue>
#include <stack>
#include <set>
#include <map>
#include <bitset>
#include <numeric>
#include <limits>
#include <climits>
#include <cfloat>
#include <functional>
using namespace std;

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 i=0; i<m; ++i)
        cin >> b[i];

    sort(a.begin(), a.end());
    sort(b.rbegin(), b.rend());

    int ret = INT_MAX;
    do{
        int i = 0;
        for(int j=0; j<m; ++j){
            int x = b[j];
            while(i < n && a[i] <= x){
                x -= a[i];
                ++ i;
            }
            if(i == n)
                ret = min(ret, j + 1);
        }
    }while(next_permutation(a.begin(), a.end()));

    if(ret < INT_MAX)
        cout << ret << endl;
    else
        cout << -1 << endl;

    return 0;
}