#include <cstdio>
#include <iostream>
using namespace std;
#define mare 500001
long int v[mare];
int s;
FILE* nigger,*kkk;

int main ()
{
    nigger=fopen ("divk.in","r");
    kkk=fopen ("divk.out","w");

    int n,k,a,b,i,j;
    fscanf (nigger,"%d%d%d%d",&n,&k,&a,&b);
    for (i=1;i<=n;i++)
        fscanf (nigger,"%ld",&v[i]);
    for (i=2;i<=n;i++)
        v[i]=v[i-1]+v[i];
    for (i=1;i<=n-a;i++)
        for (j=i;j<=i+a;j++)
            if((v[j]-v[i+b-1])%k&&j>=b)
                s++;
    fprintf (kkk,"%d",s+1);
    return 0;
}