#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;
long long 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;
        //cout<<s[i]<<" ";
	}
	//cout<<"\n\n";

    cu_rest[s[0]%k] = 1;
    for(i=1; i<=n; i++) {   //i = capatul drept
        //[j,i] ii buna daca s[i]%k = s[j-1]%k
        //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]]++;
        if(i - b + 1 >= 1) cu_rest[s[i-b]]--;// = max(cu_rest[s[i-b]]-1, 0);

        //cout<<"is bune secventele ["<<max(1, i-b+1)<<"->"<<max(1,i-a+1)<<", "<<i<<"].\n";
        //for(j=0; j<k; j++) cout<<cu_rest[j]<<" "; cout<<"\n";
        //cout<<"is bune secventele ["<<i-b+1<<"->"<<i-a+1<<", "<<i<<"].\n";
        //cout<<"exista "<<cu_rest[s[i]]<<" astfel de secvente.\n\n";


        sol += 1LL * cu_rest[s[i]];
	}
	cout<<sol<<"\n";
	g<<sol<<"\n";

	return 0;
}