#include "boxes.h"
#include <bits/stdc++.h>
using namespace std;
using LL = long long;
vector<LL> linear_cost(int n, int k, vector<int> p) {
vector<LL> ans(n+1); ans[0] = 0;
for (int i = 1; i <= n; ++i) {
ans[i] = 2 * p[i-1] + ans[max(0, i - k)];
}
return ans;
}
LL delivery(int n, int k, int l, int p[]) {
sort(p, p + n);
vector<int> v;
for (int i = 0; i < n; ++i) if (p[i]) v.push_back(p[i]);
n = int(v.size());
auto ca = linear_cost(n, k, v);
auto rv = v;
for (int& i : rv) i = l - i;
reverse(rv.begin(), rv.end());
auto cb = linear_cost(n, k, rv);
LL ans = 1e18;
for (int i = 0; i <= n; ++i) {
ans = min(ans, ca[i] + cb[n - i]);
}
for (int a = 0; a < n; ++a) {
for (int b = a; b < n && b - a < k; ++b) {
ans = min(ans, l + ca[a] + cb[n - b - 1]);
}
}
return ans;
}
