#include <iostream>
#include <fstream>
#include <vector>
#include <algorithm>
#include <deque>
#include <stack>
#define nmax 500005
#define kmax 100005
using namespace std;

int v[nmax], cu_rest[nmax], s[nmax];
int n, k, i, j, a, b, sol = 0;

int main() {
	ifstream f("divk.in");
	ofstream g("divk.out");

	f>>n>>k>>a>>b;

	s[0] = 0;
	for(i=1; i<=n; i++) {
        f>>v[i];
        s[i] = (s[i-1] + v[i])%k;
	}


    for(i=1; i<=n; i++) {   //i = capatul drept
        //in vectorul de resturi, adun 1 la restul s[]-ului in raport cu care formez secventa de lungime minima (a)
        //si scad 1 din numarul de resturi corespunzator s[]-ului in raport cu care formez secventa maxima (b)
        //ii un fel de numarare de resturi pe intervale de lungime data (ca intr-un deque)

        if(i - a + 1 >= 1) cu_rest[s[i-a+1]%k]++;
        if(i - b  >= 1) cu_rest[s[i-b]%k] = max(cu_rest[s[i-b]%k]-1, 0);

        //cout<<"is bune secventele ["<<max(1, i-b+1)<<"->"<<max(1,i-a+1)<<", "<<i<<"].\n";
        //cout<<"exista "<<cu_rest[s[i]%k]<<" astfel de secvente.\n\n";

        sol += cu_rest[s[i]%k];
	}
	g<<sol<<"\n";

	return 0;
}