#include<iostream>

 #include<cstdio>

 #include<cstring>

 #include<algorithm>

 #define re register

 using namespace std;

 int n,m,D,l,ans,a[],d[];

 int main(){

     scanf("%d%d%d%d",&n,&m,&D,&l);

     for(re int i=;i<=n;++i) scanf("%d",a+i);

     sort(a+,a+n+);

     for(re int i=,p=;i<=n;++i)

         if(a[i]-D*d[p]>=l) ++d[p],++ans,p=(p+)%m;//填充进去，下一个车道

     printf("%d",ans);

     return ;

 }