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

using SS = pair<int,long long>;
class SegmentTree{
    public:
    int siz = -1,n = -1;
    vector<SS> dat;
 
    SS op(SS a, SS b){return {a.first+b.first,a.second+b.second};}
    SS e(){return {0,0};}
    void renew (SS &a,SS x){
        a = op(a,x);
        //a = x; //set(pos,x)で可能.
        //その他.
    }
 
    SegmentTree(int N){init(N);}
    SegmentTree(const vector<SS> &A){//長さ配列サイズに合わせる.
        siz = 1; n = A.size();
        while(siz < n) siz *= 2;
        dat.resize(siz*2,e());
        for(int i=0; i<n; i++) dat.at(i+siz) = A.at(i);
        for(int i=siz-1; i>0; i--) dat.at(i) = op(dat.at(i*2),dat.at(i*2+1));
    }
    void init(int N){
        //全要素単位元に初期化.
        siz = 1; n = N;
        while(siz < n) siz *= 2;
        dat.assign(siz*2,e());
    }
    void init(const vector<SS> &A){//長さ配列サイズに合わせる.
        siz = 1; n = A.size();
        while(siz < n) siz *= 2;
        dat.resize(siz*2,e());
        for(int i=0; i<n; i++) dat.at(i+siz) = A.at(i);
        for(int i=siz-1; i>0; i--) dat.at(i) = op(dat.at(i*2),dat.at(i*2+1));
    }
    void set(int pos,SS x){
        pos = pos+siz;
        dat.at(pos) = x;
        while(pos != 1){
            pos = pos/2;
            dat.at(pos) = op(dat.at(pos*2),dat.at(pos*2+1));
        }
    }
    void update(int pos,SS x){
        pos = pos+siz;
        renew(dat.at(pos),x);
        while(pos != 1){
            pos = pos/2;
            dat.at(pos) = op(dat.at(pos*2),dat.at(pos*2+1));
        }
    } 
    SS findans(int l, int r){
        SS retl = e(),retr = e();
        l += siz,r += siz;
        while(l < r){
            if(l&1) retl = op(retl,dat.at(l++));
            if(r&1) retr = op(dat.at(--r),retr);
            l >>= 1; r >>= 1;
        }
        return op(retl,retr);
    }
    SS get(int pos){return dat.at(pos+siz);}
    SS rangeans(int l, int r){return findans(l,r);}
    SS allrange(){return dat.at(1);}
 
    //rightは) leftは[で 渡す&返す. 
    int maxright(const function<bool(SS)> f,int l = 0){
        //fを満たさない最小の箇所を返す なければn.
        l += siz; int r = n+siz;
        vector<int> ls,rs;
        while(l < r){
            if(l&1) ls.push_back(l++);
            if(r&1) rs.push_back(--r);
            l >>= 1; r >>= 1; 
        }
        SS okl = e();
        for(int i=0; i<ls.size(); i++){
            l = ls.at(i);
            SS now = op(okl,dat.at(l));
            if(!f(now)){
                while(l < siz){
                    l <<= 1;
                    now = op(okl,dat.at(l));
                    if(f(now)){okl = now; l++;}
                }
                return l-siz;
            } 
            okl = now;
        }
        for(int i=rs.size()-1; i>=0; i--){
            l = rs.at(i);
            SS now = op(okl,dat.at(l));
            if(!f(now)){
                while(l < siz){
                    l <<= 1;
                    now = op(okl,dat.at(l));
                    if(f(now)){okl = now; l++;}
                }
                return l-siz;
            } 
            okl = now;
        }
        return n;
    }
    int minleft(const function<bool(SS)> f,int r = -1){
        //fを満たす最小の箇所を返す なければ0.
        if(r == -1) r = n;
        int l = siz; r += siz;
        vector<int> ls,rs;
        while(l < r){
            if(l&1) ls.push_back(l++);
            if(r&1) rs.push_back(--r);
            l >>= 1; r >>= 1; 
        }
        SS okr = e();
        for(int i=0; i<rs.size(); i++){
            r = rs.at(i);
            SS now = op(dat.at(r),okr);
            if(!f(now)){
                while(r < siz){
                    r <<= 1; r++;
                    now = op(dat.at(r),okr);
                    if(f(now)){okr = now; r--;}
                }
                return r+1-siz;
            }
            okr = now;
        }
        for(int i=ls.size()-1; i>=0; i--){
            r = ls.at(i);
            SS now = op(dat.at(r),okr);
            if(!f(now)){
                while(r < siz){
                    r <<= 1; r++;
                    now = op(dat.at(r),okr);
                    if(f(now)){okr = now; r--;}
                }
                return r+1-siz;
            }
            okr = now;
        }
        return 0;
    }
};

int main(){
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);

    int N,K,D; cin >> N >> K >> D;
    vector<long long> H(N);
    for(auto &h : H) cin >> h;
    auto X = H;
    sort(X.begin(),X.end());
    X.erase(unique(X.begin(),X.end()),X.end());
    
    int n = X.size();
    for(auto &h : H) h = lower_bound(X.begin(),X.end(),h)-X.begin();
    SegmentTree Z(n);
    for(int i=0; i<K-1; i++) Z.update(H.at(i),{1,X.at(H.at(i))});

    int border = -1;
    auto f = [&](SS x) -> bool {return x.first<border;};

    long long answer = 1e18;
    for(int i=K-1; i<N; i++){
        Z.update(H.at(i),{1,X.at(H.at(i))});
        int low = 0,high = K/2+1;
        while(high-low > 1){
            int mid = (high+low)/2;
            border = mid;
            int l = Z.maxright(f),r = Z.minleft(f);
            if(X.at(r-1)-X.at(l) <= D) high = mid;
            else low = mid;
        }
        if(high > 1){
            border = high;
            int l = Z.maxright(f),r = Z.minleft(f);
            SS L = Z.rangeans(0,l),R = Z.rangeans(r,n);
            auto xl = X.at(l),xr = X.at(r-1);
            long long now = xl*L.first-L.second + R.second-xr*R.first;
            now -= (D-(xr-xl))*low;
            answer = min(answer,now);
        }
        else answer = 0;
        Z.update(H.at(i+1-K),{-1,-X.at(H.at(i+1-K))});
    }
    cout << answer << endl;
}