#include <iostream.h>
#include <fstream.h>

long  r[500000],s,n,k,a,b,x,nr,i,j;

int main()
{
	fstream f("divk.in",ios::in);
	fstream g("divk.out",ios::out);
	f>>n>>k>>a>>b;
	s=0;
	for (i=1;i<=n;i++)
	{
		f>>x;
		s=s+x;
		r[i]=s%k;
	}
	r[0]=0;
	nr=0;
	for (i=0;i<=n-a;i++)
		for (j=i+a;(j<=i+b)&&(j<=n);j++) if (r[i]==r[j]) nr++;
	g<<nr;
	f.close();
	g.close();
	return 0;
}