#include "boxes.h"
#include <bits/stdc++.h>
using namespace std;
const long long INF = 1e18;
template <class T1, class T2>
inline bool minimise(T1 &x, T2 y) {
if (x > y) { x = y; return true; }
return false;
}
long long delivery(int N, int K, int L, int pos[]) {
vector<int> lefts, rights;
for (int i = 0; i < N; i++) {
if (2 * pos[i] < L)
lefts.push_back(pos[i]);
else
rights.push_back(L - pos[i]);
}
sort(lefts.begin(), lefts.end(), greater<int>());
sort(rights.begin(), rights.end(), greater<int>());
/*
cerr << "K = " << K << endl;
cerr << "lefts = ";
for (int e : lefts)
cerr << e << " ";
cerr << endl;
cerr << "rights = ";
for (int e : rights)
cerr << e << " ";
cerr << endl;
*/
vector<long long> sum_lefts(lefts.size()), sum_rights(rights.size());
for (int i = int(lefts.size() - 1); i >= 0; i--) {
sum_lefts[i] = lefts[i];
if (i + K < int(lefts.size()))
sum_lefts[i] += sum_lefts[i + K];
}
for (int i = int(rights.size() - 1); i >= 0; i--) {
sum_rights[i] = rights[i];
if (i + K < int(rights.size()))
sum_rights[i] += sum_rights[i + K];
}
/*
cerr << "sum_lefts = ";
for (int e : sum_lefts)
cerr << e << " ";
cerr << endl;
cerr << "sum_rights = ";
for (int e : sum_rights)
cerr << e << " ";
cerr << endl;
*/
long long ans = 2 * (sum_lefts.front() + sum_rights.front());
for (int i = 0; i <= K; i++) {
long long cur = 1LL * L;
//cerr << "i = " << i;
//cerr << " => cur = " << cur;
if (i < int(lefts.size()))
cur += 2 * sum_lefts[i];
if (K - i < int(rights.size()))
cur += 2 * sum_rights[K - i];
//cerr << " => cur = " << cur << endl;
minimise(ans, cur);
}
cerr << "return ans = " << ans << endl;
return ans;
}
