#include<cstdio>
using namespace std;

int main()
{
	freopen("groupa.in","r",stdin);
	freopen("groupa.out","w",stdout);
	int sum=0,n,a[51],l,r,i,j,sl,sr,ci=0;
	scanf("%d",&n);
	for(i=1;i<=n;i++)
	{
		scanf("%d",&a[i]);
	    sum+=a[i];
	}
	scanf("%d%d",&l,&r);
	sl=l*n;
	sr=r*n;
	if(sum<sl||sum>sr)
	{
		printf("-1");
		return 0;
	}
	int zheng=0,fu=0,t;
	for(i=1;i<=n;i++)
	{
		if(a[i]>r)
		{
            t=a[i]-r;
			zheng+=t;
		}
		if(a[i]<l)
		{
			t=l-a[i];
			fu+=t;
		}
	}
	if(fu>zheng)
		printf("%d",fu);
	else
		printf("%d",zheng);
	return 0;
}