#include<fstream>

using namespace std;

int i,j,z,a[51],b[51],mx,n,r,l;

int main()
{
	ifstream fin("groupa.in");
	ofstream fout("groupa.out");
	fin>>n;
	for(i=1;i<=n;i++)
	{
		fin>>a[i];
		z+=a[i];
		b[i]=0;
	}
	fin>>r>>l;
	if((z/n<r)||(z/n>l))
	{
		fout<<'-1'<<endl;
		fin.close();
		fout.close();
		return 0;
	}
	z=0;
	for(i=1;i<=n;i++)
	{
		if(a[i]<r)
			b[i]=-(r-a[i]);
		if(a[i]>l)
			b[i]=a[i]-l;
		z+=b[i];
	}
	if(z<0)
	{
		for(i=1;i<=n;i++)
			if(b[i]>0)
				mx+=b[i];
		mx+=-z;
		fout<<mx<<endl;
	}
	if(z>=0)
	{
		for(i=1;i<=n;i++)
			if(b[i]>0)
				mx+=b[i];
		fout<<mx<<endl;
	}
	fin.close();
	fout.close();
	return 0;
}