//#include <tourist>
#include <bits/stdc++.h>
//#include <atcoder/all>
using namespace std;
//using namespace atcoder;
typedef long long ll;
typedef unsigned int uint;
typedef unsigned long long ull;
typedef pair<ll, ll> p;
const int INF = 1e9;
const ll LINF = ll(1e18);
const int MOD = 1000000007;
const int dx[4] = {0, 1, 0, -1}, dy[4] = {-1, 0, 1, 0};
const int Dx[8] = {0, 1, 1, 1, 0, -1, -1, -1}, Dy[8] = {-1, -1, 0, 1, 1, 1, 0, -1};
#define yes cout << "Yes" << endl
#define YES cout << "YES" << endl
#define no cout << "No" << endl
#define NO cout << "NO" << endl
#define rep(i, n) for (int i = 0; i < n; i++)
#define FOR(i, m, n) for (int i = m; i < n; i++)
#define ALL(v) v.begin(), v.end()
#define debug(v)          \
    cout << #v << ":";    \
    for (auto x : v)      \
    {                     \
        cout << x << ' '; \
    }                     \
    cout << endl;
template <class T>
bool chmax(T &a, const T &b)
{
    if (a < b)
    {
        a = b;
        return 1;
    }
    return 0;
}
template <class T>
bool chmin(T &a, const T &b)
{
    if (b < a)
    {
        a = b;
        return 1;
    }
    return 0;
}
//cout<<fixed<<setprecision(15);有効数字15桁
//-std=c++14
//g++ yarudake.cpp -std=c++17 -I .
ll gcd(ll a, ll b) { return b ? gcd(b, a % b) : a; }
ll lcm(ll a, ll b) { return a / gcd(a, b) * b; }
int main()
{
    cin.tie(0);
    ios::sync_with_stdio(false);
    int n, m;
    cin >> n;
    vector<int> a(n);
    rep(i, n) cin >> a[i];
    cin >> m;
    vector<int> b(m);
    rep(i, m) cin >> b[i];
    sort(ALL(a));
    sort(ALL(b), greater<int>());
    int ans = INF;
    do
    {
        vector<int> c = b;
        int j = 0;
        rep(i, n)
        {
            while (j != m && b[j] - a[i] < 0)
            {
                j++;
            }
            if (j == m)
            {
                break;
            }
            b[j] -= a[i];
        }
        chmin(ans, j+1);
        b = c;
        //cout<<ans<<"\n";
    }while(next_permutation(ALL(a)));
    if (ans == m + 1)
        cout << -1 << "\n";
    else
        cout << ans << "\n";
}