#include<fstream>
using namespace std;

int a[500001],v[100001],i,n,k,x,y,t;
long long sol;

int main()
{
	ifstream f("divk.in");
	ofstream g("divk.out");
	f >> n >> k >> x >> y;
	for (i=1;i<=n;i++)
	{
		f >> t;
		a[i]=(a[i-1]+t)%k;
	}
	for (i=x+1;i<=n;i++)
	{
		v[a[i-x]]++;
		if (i>y)
			v[a[i-y]]--;
		else if (a[i]==0)
			sol++;
		sol+=v[a[i]];
	}
	g << sol;
	return 0;
}