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

int main(void) {
  constexpr int inf = 987'654'321;
  int N; scanf("%d", &N);
  vector<int> A(N);
  for(int i=0; i<N; ++i) { scanf("%d", &A[i]); }
  int M; scanf("%d", &M);
  vector<int> B(M);
  for(int k=0; k<M; ++k) { scanf("%d", &B[k]); }
  vector<int> memo(1<<N);
  for(int S0=0; S0<1<<N; ++S0) {
    for(int i=0; i<N; ++i) {
      if(S0 >> i & 1) { memo[S0] += A[i]; }
    }
  }
  // dp[ここまでの箱で][おもちゃの集合] := 最小のおもちゃ箱の個数
  vector<vector<int>> dp(M+1, vector<int>(1<<N, inf));
  dp[0][0] = 0;
  for(int k=0; k<M; ++k) {
    for(int S0=0; S0<1<<N; ++S0) {
      dp[k+1][S0] = dp[k][S0];
      for(int T0=S0; T0; T0=--T0 & S0) {
        if(memo[T0] <= B[k]) {
          dp[k+1][S0] = min(dp[k+1][S0], dp[k][S0 & ~T0] + 1);
        }
      }
    }
  }
  int res = dp[M][(1<<N)-1];
  if(res == inf) { res = -1; }
  printf("%d\n", res);
  return 0;
}