#include <stdio.h>
#include <bits/stdc++.h>
#include <atcoder/all>
using namespace atcoder;
using mint = modint998244353;
using namespace std;
#define rep(i,n) for (int i = 0; i < (n); ++i)
#define Inf 1000000

int main(){
	
	int N;
	cin>>N;
	
	vector<int> a(N);
	rep(i,N)cin>>a[i];
	
	vector<int> sum(1<<N,0);
	rep(i,1<<N){
		rep(j,N){
			if((i>>j)&1)sum[i] += a[j];
		}
	}
	
	int M;
	cin>>M;
	vector<int> b(M);
	
	rep(i,M){
		cin>>b[i];
	}
	
	vector<int> dp(1<<N,Inf);
	dp[0] = 0;
	
	rep(i,M){
		vector<int> ndp(1<<N,Inf);
		for(int j=(1<<N)-1;j>=0;j--){
			if(dp[j]==Inf)continue;
			ndp[j] = min(ndp[j],dp[j]);
			
			rep(k,1<<N){
				if(sum[k] <= b[i])ndp[j|k] = min(ndp[j|k],dp[j]+1);
			}
			
		}
		swap(dp,ndp);
	}
	
	int ans = dp.back();
	if(ans==Inf)ans = -1;
	
	cout<<ans<<endl;
	
	return 0;
}