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

#define RREP(i,s,e) for (i = s; i >= e; i--)
#define rrep(i,n) RREP(i,n,0)
#define REP(i,s,e) for (i = s; i < e; i++)
#define rep(i,n) REP(i,0,n)
#define INF 1e8

typedef long long ll;

int main() {
    int i, j, k, l, n, m;
    bool dp[11][1024] {};
    int a[10], b[10];
    cin >> n;
    rep (i,n) cin >> a[i];
    cin >> m;
    rep (i,m) cin >> b[i];
    sort(b,b+m,greater<int>{});
    dp[0][0] = true;
    REP (i,1,11) {
        rep (j,pow(2,n)) {
            if (dp[i-1][j]) {
                rep (k,pow(2,n)) {
                    if ((~j & k) == k) {
                        int sum = 0;
                        rep (l,n) {
                            if (k & (1<<l))
                                sum += a[l];
                        }
                        if (b[i-1] >= sum)
                            dp[i][j|k] = true;
                    }
                }
            }
        }
    }
    rep (i,11) {
        if (dp[i][(int)pow(2,n)-1]) {
            cout << i << endl;
            return 0;
        }
    }
    cout << -1 << endl;
    return 0;
}