#include<iostream>
#include<algorithm>
using namespace std;
const int size=1e5+10;
int n;
int d[size];
int x,y;
int dist;
int ans;

bool dfs(int i,int sum,int c)
{
	//cout << i << endl;
	if(c>2)return false;
	if(sum>dist)return false;
	if(i>n)return false;
	if(sum==dist)
	{
		ans=min(ans,sum);
		return true;
	}
	
	if(dfs(i+1,sum,c))return true;
	if(dfs(i+1,sum+d[i],c+1))return true;
	
	return false;
}

int main()
{
	
	cin >> n;
	for(int i=0;i<n;i++)cin >> d[i];
	cin >> x >> y;
	
	dist=abs(x)+abs(y);
	
	//1
	ans=1;
	for(int i=0;i<n;i++)
	{
		if(dist==d[i])
		{
			cout << ans << endl;
			return 0;
		}
	}
	
	//2
	ans=2;
	sort(d,d+n,greater<int>());
	if(dfs(0,0,0))cout << ans << endl;
	else cout << -1 << endl;
	
	return 0;
}