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

#define _p(...) (void)printf(__VA_ARGS__)
#define forr(x,arr) for(auto&& x:arr)
#define _overload3(_1,_2,_3,name,...) name
#define _rep2(i,n) _rep3(i,0,n)
#define _rep3(i,a,b) for(int i=int(a);i<int(b);++i)
#define rep(...) _overload3(__VA_ARGS__,_rep3,_rep2,)(__VA_ARGS__)
#define _rrep2(i,n) _rrep3(i,0,n)
#define _rrep3(i,a,b) for(int i=int(b)-1;i>=int(a);i--)
#define rrep(...) _overload3(__VA_ARGS__,_rrep3,_rrep2,)(__VA_ARGS__)
#define ALL(x) (x).begin(), (x).end()
#define BIT(n) (1LL<<(n))
#define SZ(x) ((int)(x).size())
#define fst first
#define snd second
typedef vector<int> vi;typedef vector<vi> vvi;typedef pair<int,int> pii;typedef vector<pii> vpii;
typedef long long ll;

void Main() {
  int N, M;
  scanf("%d", &N);
  vi A(N);
  rep(i, N) scanf("%d", &A[i]);
  scanf("%d", &M);
  vi B(M);
  rep(i, M) scanf("%d", &B[i]);

  sort(ALL(B), greater<int>());

  vpii dp(BIT(N), {1e9, 1e9});
  dp[0] = {0, 0};

  rep(mask, BIT(N)) if (dp[mask].fst < 1e9) {
    int b = dp[mask].fst;
    int u = dp[mask].snd;
    rep(i, N) if ((mask & BIT(i)) == 0) {
      int a = A[i];
      int mask2 = mask | BIT(i);
      if (B[b] - u >= a) {
        dp[mask2] = min(dp[mask2], {b, u + a});
      }
      else if (b + 1 < M && B[b+1] >= a) {
        dp[mask2] = min(dp[mask2], {b + 1, a});
      }
    }
  }
  //rep(i,SZ(dp)) cout<<"dp["<<i<<"]: "<<dp[i].fst<<","<<dp[i].snd<<endl;

  int all = BIT(N)-1;

  if (dp[all].fst == 1e9) puts("-1");
  else _p("%d\n", dp[all].fst + 1);
}
int main() { cin.tie(0); ios::sync_with_stdio(false); Main(); return 0; }