#include <bits/stdc++.h>

using namespace std;
typedef long long ll;
typedef pair<ll, ll> p_ll;

template<class T>
void debug(T itr1, T itr2) { auto now = itr1; while(now<itr2) { cout << *now << " "; now++; } cout << endl; }
#define repr(i,from,to) for (int i=(int)from; i<(int)to; i++)
#define all(vec) vec.begin(), vec.end()
#define rep(i,N) repr(i,0,N)
#define per(i,N) for (int i=(int)N-1; i>=0; i--)

const ll MOD = pow(10,9)+7;
const ll LLINF = pow(2,61)-1;
const int INF = pow(2,30)-1;

vector<ll> fac;
void c_fac(int x=pow(10,6)+10) { fac.resize(x,true); rep(i,x) fac[i] = i ? (fac[i-1]*i)%MOD : 1; }
ll inv(ll a, ll m=MOD) { ll b = m, x = 1, y = 0; while (b!=0) { int d = a/b; a -= b*d; swap(a,b); x -= y*d; swap(x,y); } return (x+m)%m; }
ll nck(ll n, ll k) { return fac[n]*inv(fac[k]*fac[n-k]%MOD)%MOD; }
ll gcd(ll a, ll b) { if (a<b) swap(a,b); return b==0 ? a : gcd(b, a%b); }
ll lcm(ll a, ll b) { return a/gcd(a,b)*b; }


int main() {
  int N; cin >> N;
  int A[N]; rep(i,N) cin >> A[i];
  int M; cin >> M;
  int B[M]; rep(i,M) cin >> B[i];

  vector<vector<int>> dp(M+1, vector<int>(1<<N, INF)); dp[0][0] = 0;
  rep(i,M) rep(j,1<<N) {
    dp[i+1][j] = dp[i][j];
    for (int k=j; k>0; k=(k-1)&j) {
      int sum = 0; rep(l,N) if (k&(1<<l)) sum += A[l];
      if (sum<=B[i]) dp[i+1][j] = min(dp[i+1][j], dp[i][j-k]+1);
    }
  }
  // rep(i,M+1) debug(all(dp[i]));
  int result = dp[M][(1<<N)-1]; if (result==INF) result = -1;
  cout << result << endl;
  return 0;
}