#include <stdio.h>

FILE *in, *out;

long int n,k,a,b,i,rez,s[500005],v[500005];

int main()
{
	in=fopen("divk.in","r");
	out=fopen("divk.out","w");
	
	fscanf(in,"%ld %ld %ld %ld\n",&n,&k,&a,&b);
	
	for(i=1;i<=n;i++)
	{	
		fscanf(in,"%ld\n",&s[i]);
		
		s[i]+=s[i-1];
	}
	
	for(i=0;i<=b-a;i++)
	{
		v[s[i]%k]++;
		
		rez+=v[s[i+a]%k];
	}	
	
	v[0]--;
	
	for(i=b-a+1;i<=n-a;i++)
	{
		v[s[i-(b-a)]%k]--;
		v[s[i]%k]++;
		
		rez+=v[s[i+a]%k];
		
	}	
	
	fprintf(out,"%ld",rez);
	
	fclose(out);
	
	return 0;
}