/**
	author:  shobonvip
	created: 2025.10.29 12:41:29
**/

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

//* ATCODER
#include<atcoder/all>
using namespace atcoder;
typedef modint998244353 mint;
//*/

/* BOOST MULTIPRECISION
#include<boost/multiprecision/cpp_int.hpp>
using namespace boost::multiprecision;
//*/

typedef long long ll;

#define rep(i, s, n) for (int i = (int)(s); i < (int)(n); i++)
#define rrep(i, s, n) for (int i = (int)(n)-1; i >= (int)(s); i--)
#define all(v) v.begin(), v.end()

template <typename T> bool chmin(T &a, const T &b) {
	if (a <= b) return false;
	a = b;
	return true;
}

template <typename T> bool chmax(T &a, const T &b) {
	if (a >= b) return false;
	a = b;
	return true;
}

template <typename T> T max(vector<T> &a){
	assert(!a.empty());
	T ret = a[0];
	for (int i=0; i<(int)a.size(); i++) chmax(ret, a[i]);
	return ret;
}

template <typename T> T min(vector<T> &a){
	assert(!a.empty());
	T ret = a[0];
	for (int i=0; i<(int)a.size(); i++) chmin(ret, a[i]);
	return ret;
}

template <typename T> T sum(vector<T> &a){
	T ret = 0;
	for (int i=0; i<(int)a.size(); i++) ret += a[i];
	return ret;
}


int main(){
	ios_base::sync_with_stdio(false);
	cin.tie(NULL);
	
	int n, k;
	cin >> n >> k;
	ll d; cin >> d;
	vector<ll> h(n);
	vector<ll> v;
	v.push_back(ll(-1e18));
	rep(i,0,n) {
		cin >> h[i];
		v.push_back(h[i]);
		v.push_back(h[i]+d);
	}
	sort(all(v));
	v.erase(unique(all(v)),v.end());

	fenwick_tree<int> seg((int)v.size());

	vector<int> a(n), b(n);
	rep(i,0,n) {
		a[i] = int(lower_bound(all(v),h[i]) - v.begin());
		b[i] = int(lower_bound(all(v),h[i] + d) - v.begin());
	}

	rep(i,0,k) {
		seg.add(0, -1);
		seg.add(a[i], +1);	
		seg.add(b[i], +1);	
	}

	vector<pair<ll,int>> lower;
	vector<pair<ll,int>> upper;

	rep(i,0,n-k+1) {
		int ub = (int)v.size()-1; // ok
		int lb = -1; // ng;
		while(ub-lb>1){
			int t=(ub+lb)/2;
			if(seg.sum(0,t+1)>=0) {
				ub=t;
			}else{
				lb=t;
			}
		}

		ll targ = v[ub];
		lower.push_back(pair(targ, i));
		upper.push_back(pair(targ + d, i));
		if (i == n-k) break;
		seg.add(0, -1);
		seg.add(a[i+k], +1);	
		seg.add(b[i+k], +1);	
		seg.add(0, +1);
		seg.add(a[i], -1);	
		seg.add(b[i], -1);	
	}

	rep(i,0,n) {
		lower.push_back(pair(h[i], ~i));
		upper.push_back(pair(h[i], ~i));
	}

	sort(all(lower));
	sort(all(upper));
	reverse(all(upper));

	vector<ll> ans(n-k+1);

	{
		fenwick_tree<ll> seg2(n);
		fenwick_tree<ll> seg3(n);
		for (auto [val, i]: lower) {
			if (i < 0) {
				i = ~i;
				seg2.add(i, val);
				seg3.add(i, 1);
			} else {
				ans[i] += seg3.sum(i, i+k) * val - seg2.sum(i, i+k);
			}
		}

	}
	{
		fenwick_tree<ll> seg2(n);
		fenwick_tree<ll> seg3(n);
		for (auto [val, i]: upper) {
			if (i < 0) {
				i = ~i;
				seg2.add(i, val);
				seg3.add(i, 1);
			} else {
				ans[i] += - seg3.sum(i, i+k) * val + seg2.sum(i, i+k);

			}
		}
		
	}

	cout << min(ans) << '\n';




}