#include<bits/stdc++.h>
using namespace std;
#define rep(i,n) for(ll i=0;i<n;i++)
#define repl(i,l,r) for(ll i=(l);i<(r);i++)
#define per(i,n) for(ll i=(n)-1;i>=0;i--)
#define perl(i,r,l) for(ll i=(r)-1;i>=l;i--)
#define fi first
#define se second
#define pb push_back
#define ins insert
#define pqueue(x) priority_queue<x,vector<x>,greater<x>>
#define all(x) (x).begin(),(x).end()
#define CST(x) cout<<fixed<<setprecision(x)
#define rev(x) reverse(x);
using ll=long long;
using vl=vector<ll>;
using vvl=vector<vector<ll>>;
using pl=pair<ll,ll>;
using vpl=vector<pl>;
using vvpl=vector<vpl>;
const ll MOD=1000000007;
const ll MOD9=998244353;
const int inf=1e9+10;
const ll INF=4e18;
const ll dy[9]={1,0,-1,0,1,1,-1,-1,0};
const ll dx[9]={0,-1,0,1,1,-1,1,-1,0};
template<class T> inline bool chmin(T& a, T b) {
    if (a > b) {
        a = b;
        return true;
    }
    return false;
}
template<class T> inline bool chmax(T& a, T b) {
    if (a < b) {
        a = b;
        return true;
    }
    return false;
}

int main(){
    ll n;cin >> n;
    vl v(n);rep(i,n)cin >> v[i];
    ll m;cin >> m;
    vl w(m);rep(i,m)cin >> w[i];
    sort(all(w));rev(all(w));
    rep(i,m){
        vl W=w;while(W.size()!=i+1)W.pop_back();
        set<vl> st,nst;
        st.insert(W);
        rep(j,n){
            for(auto &p:st){
                rep(k,i+1){
                    if(p[k]>=v[j]){
                        vl z=p;
                        z[k]-=v[j];
                        nst.ins(z);
                    }
                }
            }
            st=nst;
            nst.clear();
        }
        if(st.size())cout << i+1 <<endl,exit(0);
    }
    cout << -1 <<endl;
}