#include <bits/stdc++.h>
#define EPS 1e-9
#define INF 1070000000LL
#define MOD 1000000007LL
#define fir first
#define foreach(it,X) for(auto it=(X).begin();it!=(X).end();it++)
#define numa(x,a) for(auto x: a)
#define ite iterator
#define mp make_pair
#define mt make_tuple
#define rep(i,n) rep2(i,0,n)
#define rep2(i,m,n) for(int i=m;i<(n);i++)
#define pb push_back
#define pf push_front
#define sec second
#define sz(x) ((int)(x).size())
#define ALL( c ) (c).begin(), (c).end()
#define gcd(a,b) __gcd(a,b)
#define mem(x,n) memset(x,n,sizeof(x))
#define endl "\n"
using namespace std;
template <int POS, class TUPLE> void deploy(std::ostream &os, const TUPLE &tuple){}
template <int POS, class TUPLE, class H, class ...Ts> void deploy(std::ostream &os, const TUPLE &t){ os << (POS == 0 ? "" : ", ") << get<POS>(t); deploy<POS + 1, TUPLE, Ts...>(os, t); }
template <class T> std::ostream& operator<<(std::ostream &os, std::vector<T> &v){ int remain = v.size(); os << "{"; for(auto e: v) os << e << (--remain == 0 ? "}" : ", "); return os; }
template <class T> std::ostream& operator<<(std::ostream &os, std::set<T> &v){ int remain = v.size(); os << "{"; for(auto e: v) os << e << (--remain == 0 ? "}" : ", "); return os; }
template <class T, class K> std::ostream& operator<<(std::ostream &os, std::map<T, K> &mp){ int remain = mp.size(); os << "{"; for(auto e: mp) os << "(" << e.first << " -> " << e.second << ")" << (--remain == 0 ? "}" : ", "); return os; }
#define DEBUG1(var0) { std::cerr << (#var0) << "=" << (var0) << endl; }
#define DEBUG2(var0, var1) { std::cerr << (#var0) << "=" << (var0) << ", ";DEBUG1(var1); }
#define DEBUG3(var0, var1, var2) { std::cerr << (#var0) << "=" << (var0) << ", ";DEBUG2(var1,var2); }
#define DEBUG4(var0, var1, var2, var3) { std::cerr << (#var0) << "=" << (var0) << ", ";DEBUG3(var1,var2,var3); }
using ll = long long;

int N,M;
int nums[11];
int nums2[11];
int sums_num[1<<10+10];
int memo[1<<10+10][12];
int dp_go(int mask,int now){
  if(now == N){
    if(mask == 0){
      return 0;
    }else{
      return INF;
    }
  }
  if(memo[mask][now] >= 0){
    return memo[mask][now];
  }
  int ret = dp_go(mask,now+1);
  for(int now_use = mask;now_use > 0;now_use = (now_use-1)&mask){
    if(sums_num[now_use] <= nums2[now]){
      //DEBUG1(now_use);
      //DEBUG1(mask^now);
      ret = min(ret,dp_go(mask^now_use,now+1)+1);
    }
  }
  //DEBUG3(mask,now,ret);
  return memo[mask][now] = min((int)INF,ret);
}
int main(){
  cin.tie(0);
  ios_base::sync_with_stdio(0);
  cin >> N;
  rep(i,N){
    cin >> nums[i];
  }
  mem(memo,-1);
  cin >> M;
  rep(i,M){
    cin >> nums2[i];
  }
  rep(k,1<<N){
    int sums = 0;
    rep(i,N){
      if(k & (1<<i)){
        sums += nums[i];
      }
    }
    sums_num[k] = sums;
  }
  int x = dp_go((1<<N)-1,0);
  if(x == INF){
    cout << -1 << endl;
  }else{
    cout << x << endl;
  }
  return 0;
}