#include <bits/stdc++.h>
using namespace std;
#define rep(i,n) for(int (i) = 0 ; (i) < (int)(n) ; (i)++)
#define REP(i,a,b) for(int (i) = a ; (int)(i) <= (int)(b) ; (i)++)
#define all(n) (n).begin(),(n).end()
typedef long long ll;
typedef vector<int> Vi;
typedef vector<Vi> VVi;
typedef pair<long long,long long> Pii;
typedef vector<Pii> VPii;


int A[10],B[10];

vector<int> item[10];


int dp[10][1<<10];
int dfs(int x,int bit){
	if( x < 0 ) return bit == 0 ? 0 : 1e9;
	if( dp[x][bit] != -1 ) return dp[x][bit];
	int ans = dfs(x-1,bit);
	for( auto i : item[x] )
		if( (bit&i) == i ) {
			
			ans = min(ans,dfs(x-1,bit-i)+1);
		}
	return dp[x][bit] = ans;
}
int main(){
	int N;
	cin >> N;
	rep(i,N) cin >> A[i];
	int M;
	cin >> M;
	rep(i,M) cin >> B[i];
	rep(i,M)rep(j,1<<N){
		int t = 0;
		rep(k,N) t += A[k]*(j>>k&1);
		if(t<=B[i]){
			item[i].push_back(j);
		}
	}
	memset(dp,-1,sizeof(dp));
	int ans = dfs(M-1,(1<<N)-1);
	if( ans > 114514 ) cout << -1 << endl;
	else cout << ans << endl;
}