#include <iostream>
#include<cstdio>
using namespace std;
const int K=100005;
const int N=500005;
int frv[K];
int sp[N];
int main()
{
    FILE*fin,*fout;
    fin=fopen("divk.in","r");
    fout=fopen("divk.out","w");
    int n,a,b,k;
    fscanf(fin,"%d%d%d%d",&n,&k,&a,&b);
    for(int i=1;i<=n;i++){
      int x;
      fscanf(fin,"%d",&x);
      sp[i]=x+sp[i-1];
      sp[i]%=k;
    }
    long long sol=0;
    for(int i=a;i<=n;i++){
      frv[sp[i-a]]++;
      if(i>b)
        frv[sp[i-b-1]]--;
      sol+=1LL*frv[sp[i]];
    }
    fprintf(fout,"%lld",sol);
    return 0;
}