#include <cstdio>
#include <cstring>
#include <iostream>
#include <vector>
#include <algorithm>
#include <set>
#include <stack>
#include <queue>
#include <list>
//#include <windows.h>
//#include <conio.h>
#include <cstdlib>
#include <time.h>
#include <limits.h>
#include <string>
#include <math.h>
using namespace std;
#define forA(V,it) for (typeof(V.begin()) it=V.begin();it!=V.end();it++)
#define pb push_back
#define mp make_pair
#define fi first
#define se second
#define ll long long
#define ull unsigned ll
#define MOD 1000000007
#define INF (1<<31)-1
#define MINF -(1<<31)
#define vi vector <int>
#define vll vector <ll>
#define pii pair <int,int>
#define pll pair <ll,ll>
#define newl printf("\n")
#define DIM 1000000
int N,K,A,B,i,S[500005],v[100005],sol;
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",&S[i]);
        S[i]=(S[i]+S[i-1])%K;
    }
    for (i=1;i<=N;i++)
    {
        if (i>=A) v[S[i-A]]++;
        if (i>B) v[S[i-B-1]]--;
        sol+=v[S[i]];
    }
    printf("%d",sol);
    return 0;
}