#include "boxes.h"
#include <bits/stdc++.h>
#pragma GCC target("lzcnt,popcnt")
#pragma GCC optimize("O3,unroll-loops")
#define int long long
#define pii pair<int,int>
#define vi vector<int>
#define ff first
#define ss second
#define all(x) x.begin(),x.end()
#define sp << " " <<
using namespace std;
int delivery(int32_t N, int32_t K, int32_t L, int32_t p[]) {
vi sol,sag;
for (int i = 0;i<N;i++) {
if (p[i] <= L/2) sag.push_back(p[i]);
else break;
}
for (int i = N-1;i>=0;i--) {
if (p[i] > L/2) sol.push_back(p[i]);
else break;
}
int ans = 0;
while (sag.size() >= K) {
ans+=2*sag.back();
for (int j = 0;j<K;j++) sag.pop_back();
}
while (sol.size() >= K) {
ans+=2*(L-sol.back());
for (int j = 0;j<K;j++) sol.pop_back();
}
int op1 = ((sol.empty())?0ll:(2*(L-sol.back())))+((sag.empty())?0ll:(2*sag.back()));
vi lst;
for (auto it : sag) lst.push_back(it);
for (int i = sol.size()-1;i>=0;i--) lst.push_back(sol[i]);
int op2 = 2e18;
if (lst.size() <= K) op2 = L;
else {
op2 = L+2*min(L-lst[K],lst[lst.size()-K-1]);
}
return ans+min(op1,op2);
}
