#include <bits/stdc++.h>
using namespace std;

int main(){
  long n,c,k;
  cin >> n >> c >> k;
  long t[n];
  for(long i=0;i<n;i++)
    cin >> t[i];
  sort(t,t+n);
  long bus=0;
  for(long i=0;i<n;){
    long a = t[i];
    long j=i+1;
    while(t[j]<=a+k&&j<n)
      j++;
    i+=min(c,j-i);
    bus++;
  }
  cout << bus << endl;
}
