#include <bits/stdc++.h>
#include "boxes.h"
#define N 10000005
#define ll long long
#define ff first
#define ss second
using namespace std;
ll p[N], s[N];
ll delivery(int n, int k1, int l1, int a[]) {
sort(a,a+n);
ll x = l1, k = k1;
for(int i = 0; i < n; i++){
p[i+1] = a[i] + p[max(i-k+1,0ll)];
}
for(int i = n-1; i >= 0; i--){
s[i+1] = (x-a[i]) + s[min(i+k+1,(ll)(n+1))];
}
ll ans = LLONG_MAX, ind = ((x+1)/2);
vector <pair<ll,ll>> v;
for(int i = 0; i <= n; i++){
ans = min(ans,2*(p[i] + s[i+1]));
}
for(int i = 0; i < n; i++){
v.push_back({abs(ind-a[i]),i+1});
}
sort(v.begin(), v.end());
ll l = n+1, r = 0;
for(auto i : v){
l = min(l,i.ss-1);
r = max(r,i.ss+1);
ll z = (p[l] + s[r]);
z *= 2ll;
z += (((r-l-2+k)/k)*x*1ll);
ans = min(ans,z);
}
return ans;
}
