#include <bits/stdc++.h>

#define rep(i,n) for(int i=0;i<(n);i++)

using namespace std;

const int INF=1<<29;

int n,m,a[10],b[10];

int cap[10];

int dfs(int i){
	if(i==n) return m-count(cap,cap+m,0);

	int res=INF;
	rep(j,m) if(cap[j]+a[i]<=b[j]) {
		cap[j]+=a[i];
		res=min(res,dfs(i+1));
		cap[j]-=a[i];
		if(cap[j]==0) break;
	}
	return res;
}

int main(){
	scanf("%d",&n);
	rep(i,n) scanf("%d",&a[i]);
	scanf("%d",&m);
	rep(j,m) scanf("%d",&b[j]);

	sort(a,a+n,greater<int>());
	sort(b,b+m,greater<int>());

	int ans=dfs(0);
	printf("%d\n",ans<INF?ans:-1);

	return 0;
}