#include<iostream>
#include<vector>
#include<algorithm>
using namespace std;

vector<int>sorted;
vector<int>work;
vector<int> box,item;
int res=11;
int N,M;
void check(int sz){
	for(auto &it:work){
		sorted.push_back(it);
	}
	sort(sorted.begin(),sorted.end());
	reverse(sorted.begin(),sorted.end());
	bool f=true;
	for(auto i=0;i<sz;i++){
		if(sorted[i]>box[i])f=false;
	}
	if(f)res=sz;
	sorted.clear();
}

void func(int n,int sz){
	if(sz>=res)return;
	if(n==N){
		check(sz);
		return;
	}
	for(int i=0;i<sz;i++){
		work[i]+=item[n];
		func(n+1,sz);
		work[i]-=item[n];
	}
	work.push_back(item[n]);
	func(n+1,sz+1);
	work.pop_back();
}

int main(){
	sorted.reserve(10);
	work.reserve(10);
	cin>>N;
	for	(int i=0;i<N;i++){
		int x;
		cin>>x;
		item.push_back(x);
	}
	cin>>M;
	for	(int i=0;i<M;i++){
		int x;
		cin>>x;
		box.push_back(x);
	}
	sort(box.begin(),box.end());
	reverse(box.begin(),box.end());
	func(0,0);
	if(res>=11)cout<<-1<<endl;
	else cout<<res<<endl;
}