#include "boxes.h"
#pragma GCC optimize ("O3")
#pragma GCC target ("sse4")
#pragma GCC optimize ("unroll-loops")
#pragma GCC target ("avx2")
#include <bits/stdc++.h>
using namespace std;
typedef long long lo;
typedef pair< lo,lo > PII;
#define fi first
#define se second
#define mp make_pair
#define endl "\n"
#define pb push_back
#define fio() ios_base::sync_with_stdio(false);cin.tie(NULL);cout.tie(NULL)
#define FOR for(int i=1;i<=n;i++)
#define mid ((start+end)/2)
#define ort ((bas+son)/2)
const lo inf = 1000000000000000000;
const lo KOK = 100000;
const lo LOG = 30;
const lo li = 500005;
const lo mod = 1000000007;
int m,b[li],flag,t;
lo cev;
string s;
set<int> st,st1;
long long delivery(int n, int k, int l, int a[]) {
for(int i=0;i<n;i++){
cev+=min(l-a[i],a[i])*2;
}
if(k==1)return cev;
cev=0;
for(int i=0;i<n;i++){
if(a[i]<l/2)st.insert(a[i]);
else st1.insert(a[i]);
}
while((int)st.size()>=k){
int say=0;
while(say<k-1){say++;st.erase(st.begin());}
cev+=2**st.begin();
st.erase(st.begin());
}
while((int)st1.size()>=k){
int say=0;
while(say<k-1){say++;st1.erase(st1.begin());}
cev+=2*(l-*st1.begin());
st1.erase(st1.begin());
}
//~ cout<<cev<<endl;
lo mn=inf;
auto it=st.end();
if(it!=st.begin()){
it--;
int at=*it*2;
it=st1.end();
if(it!=st1.begin()){
it--;
at+=(l-*it)*2;
}
//~ cout<<at<<endl;
mn=min(mn,cev+at);
}
it=st1.end();
if(it!=st1.begin()){
it--;
int at=(l-*it)*2;
it=st.end();
if(it!=st.begin()){
it--;
at+=*it*2;
}
//~ cout<<at<<endl;
mn=min(mn,cev+at);
}
mn=min(mn,cev+((int)st.size()+(int)st1.size()+k-1)/k*l);
return mn;
}
