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

#define CIN_ONLY if(1)
struct cww{cww(){
    CIN_ONLY{
        ios::sync_with_stdio(false);cin.tie(0);
    }
}}star;
#define fin "\n"
#define FOR(i,bg,ed) for(int i=(bg);i<(ed);i++)
#define REP(i,n) FOR(i,0,n)
#define ALL(v) (v).begin(),(v).end()
#define fi first
#define se second
#define pb push_back
#define DEBUG if(0)
#define REC(ret, ...) std::function<ret (__VA_ARGS__)>
template <typename T>inline bool chmin(T &l,T r)
{bool a=l>r;if(a)l=r;return a;}
template <typename T>inline bool chmax(T &l,T r)
{bool a=l<r;if(a)l=r;return a;}
template <typename T>
istream& operator>>(istream &is,vector<T> &v){
    for(auto &it:v)is>>it;
    return is;
}
    
int main(){
    int N,M;
    cin>>N;
    vector<int> a(N);
    cin>>a;
    cin>>M;
    vector<int> b(M);
    cin>>b;
    sort(ALL(b));
    reverse(ALL(b));
    vector<int> ord(N);
    iota(ALL(ord),0);
    int res=100;
    do{
        auto c= b;
        int id=0;
        bool flag=true;
        REP(i,N){
            while(id<M){
                if(c[id]>=a[ord[i]])break;
                id++;
            }
            if(id==M){
                flag=false;
                break;
            }
            c[id]-=a[ord[i]];
        }
        if(flag)chmin(res,id+1);
    }while(next_permutation(ALL(ord)));
    if(res==100)res=-1;
    cout<<res<<endl;
    return 0;
}