#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using vll = vector<ll>;
#define all(A) A.begin(),A.end()
#define rep(i, n) for (ll i = 0; i < (ll) (n); i++)

int main() {
    ll N,M;
    cin>>N;
    vll A(N);
    rep(i,N)cin>>A[i];
    cin>>M;
    vll B(M);
    rep(i,M)cin>>B[i];
    ll an=M+20;
    sort(all(B));
    reverse(all(B));
    sort(all(A));
    do{
        ll k=0;
        ll s=0;
        rep(i,N){
            if(s+A[i]<=B[k]){
                s+=A[i];
            }
            else if(k==M-1){
                k=1e17;
                break;
            }
            else {
                k++;
                s=0;
                i--;
            }
        }
        an=min(an,k+1);
    }while(next_permutation(all(A)));
    cout<<(an<M+1?an:-1)<<endl;
}