#include <bits/stdc++.h>

using namespace std;


const int dx[] = {1, 0, -1, 0}, dy[] = {0, -1, 0, 1};

int N,M;
vector<int> A,B;
int cluster[1 << 12];
int dp[12][1 << 12];
int main(){
  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(A.begin(), A.end());
  sort(B.rbegin(), B.rend());
  for (int i = 0; i < (1 << N); i++){
    int sum = 0;
    for (int j = 0; j < N; j++){
      if (i >> j & 1){
	sum += A[j];
      }
    }
    cluster[i] = sum;
  }
  memset(dp, 0, sizeof(dp));
  dp[0][0] = 1;
  
  for (int i = 0; i < M; i++){
    for (int bit1 = 0; bit1 < (1 << N); bit1++){//pre
      for (int bit2 = 0; bit2 < (1 << N); bit2++){
	if ((bit1 & bit2) == 0){
	  if (dp[i][bit1] and cluster[bit2] <= B[i]){
	    dp[i + 1][bit1 | bit2] = 1;
	  }
	}
      }
    }
    if (dp[i + 1][(1 << N) - 1]){
      cout << i + 1 << endl;
      return 0;
    }
  }
  cout << -1 << endl;
}