#include <iostream>
#include <cstring>
using namespace std;

const int INF = 1 << 28;
const int MAX_N = 12;
const int MAX_M = 12;

int a[MAX_N], b[MAX_M];
bool pack[MAX_M][1 << MAX_N];
int dp[MAX_M][1 << MAX_N];

int main() {
    int n, m;
    cin >> n;
    for (auto i = 0; i < n; i++) {
        cin >> a[i];
    }

    cin >> m;
    for (auto i = 0; i < m; i++) {
        cin >> b[i];
    }

    memset(pack, false, sizeof(pack));
    fill((int* )dp, (int* )(dp + m + 1), INF);

    for (auto b_i = 0; b_i < m; b_i++) {
        for (auto mask = 0; mask < (1 << n); mask++) {
            int volume = 0;
            for (auto a_i = 0; a_i < n; a_i++) {
                if ((mask >> a_i) & 1) volume += a[a_i];
            }
            if (volume <= b[b_i]) pack[b_i][mask] = true;
        }
    }

    dp[0][0] = 0;
    for (auto b_i = 1; b_i <= m; b_i++) {
        for (auto mask = 0; mask < (1 << n); mask++) {
            for (auto toys = 0; toys < (1 << n); toys++) {
                if ((mask | toys) != mask || !pack[b_i - 1][toys]) continue;

                dp[b_i][mask] = min(dp[b_i][mask],
                                    dp[b_i - 1][mask & ~toys] + (toys == 0 ? 0 : 1));
            }
        }
    }

    auto ans = dp[m][(1 << n) - 1];
    if (ans < INF) cout << ans << endl;
    else cout << -1 << endl;

    return 0;
}