#include <stdio.h>

int a,b,n,k,v[500001],i,m[500001],rez;


int main()
{
	freopen("divk.in","r",stdin);
	freopen("divk.out","w",stdout);
	scanf("%d%d%d%d",&n,&k,&a,&b);
	for(i=1;i<=n;i++){
		scanf("%d",v[i]);
		v[i]+=v[i-1];
		v[i]%=k;
	}
	for(i=a;i<=n;i++){
		rez+=m[v[i]];
		m[v[i-a]]++;
		if(i>b){
			m[v[i-b-1]]--;
		}
	}
	printf("%d",rez);
}