#include <bits/stdc++.h>
using namespace std;

int main() {
    int N, M;
    vector<int> A, B;
    cin >> N;
    A.resize(N);
    for (int i = 0; i < N; i++) {
        cin >> A[i];
    }
    cin >> M;
    B.resize(M);
    for (int i = 0; i < M; i++) {
        cin >> B[i];
    }

    sort(B.begin(), B.end(), greater<int>());
    B.push_back(1000);

    int ans = M + 1;
    do {
        int now = 0;
        vector<int> C(M + 1);
        for (int i = 0; i < N; i++) {
            if (C[now] + A[i] <= B[now]) {
                C[now] += A[i];
            } else {
                now++;
                i--;
            }
        }
        ans = min(ans, now + 1);
    } while (next_permutation(A.begin(), A.end()));

    if (ans == M + 1) ans = -1;
    cout << ans << endl;
}