bus.cpp

#include<bits/stdc++.h>
using namespace std;
#define F first
#define S second
#define PB push_back
#define MP make_pair
#define REP(i,a,b) for (int i = a; i <b; i++)
typedef long long ll;
#define int ll
typedef vector<int> vi;
typedef vector<long long> vl;
typedef pair<int,int> pi;
#define trace(x) cout<<#x<<"="<<x<<"\n";
#define sz(x) (int)(x.size())
#define mod 1000000007
#define endl "\n"
template < typename F, typename S >
ostream& operator << ( ostream& os, const pair< F, S > & p ) {
    return os << "(" << p.first << ", " << p.second << ")";
}

template < typename T >
ostream &operator << ( ostream & os, const vector< T > &v ) {
    os << "{";
    typename vector< T > :: const_iterator it;
    for( it = v.begin(); it != v.end(); it++ ) {
        if( it != v.begin() ) os << ", ";
        os << *it;
    }
    return os << "}";
}

template < typename T >
ostream &operator << ( ostream & os, const set< T > &v ) {
    os << "[";
    typename set< T > :: const_iterator it;
    for ( it = v.begin(); it != v.end(); it++ ) {
        if( it != v.begin() ) os << ", ";
        os << *it;
    }
    return os << "]";
}

template < typename F, typename S >
ostream &operator << ( ostream & os, const map< F, S > &v ) {
    os << "[";
    typename map< F , S >::const_iterator it;
    for( it = v.begin(); it != v.end(); it++ ) {
        if( it != v.begin() ) os << ", ";
        os << it -> first << " = " << it -> second ;
    }
    return os << "]";
}

#define deb(x) cerr << #x << " = " << x << endl;



int32_t main(){
    ios::sync_with_stdio(false);
    int n, c, k;
    cin>>n>>c>>k;
    vi t;
    t.resize(n);
    REP(i,0,n){
        cin>>t[i];
    }
    sort(t.begin(),t.end());
    int ans=0;
    int ini=0;
    int cur=0;
    // deb(t);
    int f=0;
    // while(ini<n){
    //     deb("outside");
    //     deb(ini);
    //     while(cur<n){
    //         deb("**indide");
    //         deb(ini);
    //         deb(cur);
    //         if((t[cur]-t[ini])<=k){
    //             cur++;
    //             f=0;
    //         }
    //         else{
    //             deb(ini);
    //             deb(cur);
    //             ans++;
    //             f=1;
    //             ini=cur;
    //         }
    //     }
    //     ini++;
    // }
    // if(f==1){
    //     ans++;
    // }
    int lo=t[0];
    ans=0;
    cur=1;
    for(int i=1; i<n;i++){
        if((t[i]-lo)<=k  && cur<c){
            cur++;
        }
        else{
            ans++;
            cur=1;
            lo=t[i];
        }
    }
    ans++;
    cout<<max(ans,1LL)<<"\n";

    return 0;
}