#include<fstream>
using namespace std;
int v[100][500003];
int main()
{
	ifstream f("divk.in");
	ofstream g("divk.out");
	int n,a,b,k,i,j;
	f>>n>>k>>a>>b;
	for(i=1;i<=n;i++)
	{
		f>>j;
		v[1][i]=j%k;
	}
	long long suma=0,nr_sol=0;
	for(i=1;i<=a;i++)
		suma=(suma+v[1][i])%k;
	for(i=a;i<=n;i++)
	{
		v[2][i]=suma;
		if(v[2][i]==0) nr_sol++;
		suma=(suma-v[1][i+1-a]+v[1][i+1])%k;
	}
	for(j=a+1;j<=b;j++)
		for(i=n;i>=j;i--)
		{
			v[2][i]=(v[1][i]+v[2][i-1])%k;
			if(v[2][i]==0) nr_sol++;
		}
	g<<nr_sol;
}