#include <bits/stdc++.h>

using namespace std;

bool dfs(vector<int> &a, vector<int> &b, int pos) {
  if (pos == a.size()) return true;
  for (int i = 0; i < b.size(); i++) {
    if (b[i] >= a[pos]) {
      b[i] -= a[pos];
      bool res = dfs(a, b, pos+1);
      b[i] += a[pos];
      if (res)
        return true;
    }
  }
  return false;
}

bool check(vector<int> a, vector<int> b) {
  return dfs(a, b, 0);
}

int solve(vector<int> a, vector<int> b) {
  sort(b.begin(), b.end());
  vector<int> c;
  while (b.size()) {
    c.push_back(b.back());
    b.pop_back();
    if (check(a, c))
      return c.size();
  }
  return -1;
}

int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);

  int n, m;

  cin >> n;
  vector<int> a(n);
  for (int i = 0; i < n; i++) cin >> a[i];

  cin >> m;
  vector<int> b(m);
  for (int i = 0; i < m; i++) cin >> b[i];

  cout << solve(a, b) << endl;
  
  return 0;
}