//rezolvare O(n) - 100p
#include<cstdio>
#define infile "divk.in"
#define outfile "divk.out"
#define L 500005
using namespace std;

void rezolva();
void afiseaza();

int n;
int s[L],v[L];
long long sol=0;
int k,a,b;





void rezolva()
{
	freopen(infile,"r",stdin);
	
	int x;
	
	scanf("%d",&n);
	scanf("%d%d%d",&k,&a,&b);
	
	for(int i=1;i<=n;i++)
	{
		scanf("%d",&x);
		
		s[i]=(s[i-1]+x)%k;
		
		if(i-b-1>=0)
			--v[s[i-b-1]];
		
		if(i-a>=0)
			++v[s[i-a]];
		
		sol+=v[s[i]];
		
	}
	
	fclose(stdin);
}




void afiseaza()
{
	freopen(outfile,"w",stdout);
	
	printf("%lld",sol);
	
	fclose(stdout);
}


int main()
{
	rezolva();
	afiseaza();
	
	return 0;
}