#include "boxes.h"
#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace std;
using namespace __gnu_pbds;
//#define int long long
//#pragma GCC optimize("Ofast")
//#pragma comment(linker, "/stack:200000000")
//#pragma GCC target("sse,sse2,sse3,ssse3,sse4")
#define file(s) freopen(s".in","r",stdin); freopen(s".out","w",stdout);
#define fastio ios_base::sync_with_stdio(0), cin.tie(0), cout.tie(0);
#define all(x) x.begin(), x.end()
#define sz(s) (int)s.size()
#define pb push_back
#define ppb pop_back
#define mp make_pair
#define s second
#define f first
typedef pair < long long, long long > pll;
typedef pair < int, int > pii;
typedef unsigned long long ull;
typedef vector < pii > vpii;
typedef vector < int > vi;
typedef long double ldb;
typedef long long ll;
typedef double db;
typedef tree < int, null_type, less < int >, rb_tree_tag, tree_order_statistics_node_update > ordered_set;
const int inf = 1e9, maxn = 2e5 + 48, mod = 998244353, N = 1e7 + 12;
const int dx[] = {1, -1, 0, 0}, dy[] = {0, 0, 1, -1}, block = 300;
const pii base = mp(1171, 3307), Mod = mp(1e9 + 7, 1e9 + 9);
const db eps = 1e-12, pi = acos(-1);
const ll INF = 1e18;
ll s1[N], s2[N];
int pos[N], pp[N];
ll delivery(int n, int k, int l, int p[]) {
sort(p, p + n);
int cur = 0, cnt = 0, j = 0;
while (j < n && !p[j])
++j;
for (int i = j; i < n; ++i) {
if (cnt == k) {
cnt = 0;
pos[cur++] = i - 1;
}
++cnt;
if (!cur)
s1[i] = p[i]*2;
else
s1[i] = s1[pos[cur - 1]] + p[i]*2;
}
cur = 0, cnt = 0;
for (int i = n - 1; i >= j; --i) {
pp[i] = l - p[i];
if (cnt == k) {
cnt = 0;
pos[cur++] = i + 1;
}
++cnt;
if (!cur)
s2[i] = pp[i]*2;
else
s2[i] = s2[pos[cur - 1]] + pp[i]*2;
}
// for (int i = 0; i < n; ++i)
// cerr << s1[i] << ' ' << s2[i] << endl;
ll ans = s1[n - 1];
for (int i = 0; i < n - 1; ++i)
ans = min(ans, s1[i] + s2[i + 1]);
return ans;
}
