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

int main() {
  int N;
  cin >> N;
  vector<int> A(N);
  for (int i = 0; i < N; i++) cin >> A.at(i);
  int M;
  cin >> M;
  vector<int> B(M);
  for (int i = 0; i < M; i++) cin >> B.at(i);
  sort(A.begin(), A.end());
  sort(B.rbegin(), B.rend());
  int ans = INT_MAX;
  do {
    auto C = B;
    vector<int> D(M);
    for (auto a : A) {
      int b = 1;
      for (int i = 0; i < M; i++) {
        if (C.at(i) >= a) {
          C.at(i) -= a, D.at(i) = 1, b = 0;
          break;
        }
      }
      if (b) goto NEXT;
    }
    ans = min(ans, accumulate(D.begin(), D.end(), 0));
    NEXT:;
  } while (next_permutation(A.begin(), A.end()));
  if (ans == INT_MAX) ans = -1;
  cout << ans << "\n";
}