#include "boxes.h"
#include <vector>
#include <algorithm>
#include <iostream>
using ll = long long;
#define debug(x) #x << " = " << x << '\n'
ll delivery(int n, int k, int L, int p[]) {
std::vector<std::pair<int, int>> v(n);
for (int i = 0; i < n; i++) {
v[i].first = std::min(p[i], L - p[i]);
v[i].second = p[i];
}
std::sort(v.begin(), v.end());
std::reverse(v.begin(), v.end());
std::vector<int> st, dr;
for (int i = 0; i < n; i++) {
if (v[i].first == v[i].second) {
st.push_back(v[i].first);
} else {
dr.push_back(v[i].first);
}
}
std::sort(st.begin(), st.end());
std::sort(dr.begin(), dr.end());
ll answer = 1e18;
for (int catel = 0; catel <= (int) st.size(); catel++) { // dintre turele full, cate sterg din st?
for (int cater = 0; cater <= (int) dr.size(); cater++) {
ll cur = 0;
for (int i = (int) st.size() - catel - 1; i >= 0; i -= k) {
cur += st[i];
}
for (int i = (int) dr.size() - cater - 1; i >= 0; i -= k) {
cur += dr[i];
}
cur *= 2;
cur += (ll) L * ((catel + cater + k - 1) / k);
answer = std::min(answer, cur);
}
}
return answer;
}
