#ifdef ONPC
#define _GLIBCXX_DEBUG
#endif
#include <bits/stdc++.h>
#ifndef ONPC
#pragma GCC target("avx2")
#pragma GCC target("popcnt")
#define cerr if (false) cerr
#endif
#define all(v) v.begin(), v.end()
#define watch(x) cerr << #x << ':' << x << endl;
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
typedef pair<int, int> Pint;
typedef pair<ll, ll> Pll;
typedef __int128_t int128;
mt19937_64 gen64(chrono::steady_clock::now().time_since_epoch().count());
inline ll rnd(ll l = LLONG_MIN, ll r = LLONG_MAX) {
return uniform_int_distribution<ll>(l, r)(gen64);
}
const int mod = 1e9 + 7;
inline int mult(int a, int b) {
return (1LL * a * b) % mod;
}
template<class T>
bool umax(T &a, const T &b) {
return (a < b ? a = b, true : false);
}
const int inf = 1e9 + 10;
const ll INF = 1e18 + 10;
const int maxn = 1e5 + 10, maxm = 20, maxc = 5000 + 10, maxq = 2e5 + 10, logn = 20, msqn = 45, cpr = 500, maxbit = 32;
long long delivery(int N, int K, int L, int P[]) {
ll n = N, k = K, l = L;
vector<int> a(n);
for(int i = 0; i < n; i++)
a[i] = P[i];
sort(all(a));
vector<vector<ll>> pref(k, vector<ll>(n / k + 2));
for (int i = 0; i < n; ++i) {
pref[i % k][i / k + 1] = pref[i % k][i / k] + a[i];
}
for (int i = 0; i < k; ++i) {
while (pref[i].back() == 0) {
pref[i].pop_back();
}
}
auto get_l = [&](int i) {
return pref[i % k][i / k + 1];
};
auto get_r = [&](int i) {
return pref[i % k].back() - pref[i % k][i / k];
};
ll ans = 0;
int p = -1, q = -1, pt = 0, qt = 0;
for (auto i : a) {
if (i < l - i) {
p = max(p, i);
pt++;
} else {
i = l - i;
q = max(q, i);
qt++;
}
if (pt == k) {
ans += 2 * p;
pt = 0; p = -1;
}
if (qt == k) {
ans += 2 * q;
qt = 0; q = -1;
}
}
if (pt != 0) {
ans += 2 * p;
}
if (qt != 0) {
ans += 2 * q;
}
watch(ans);
for (int i = 0; i + k <= n; ++i) {
ll p = 0, q = 0;
if (i > 0) {
p = get_l(i - 1);
}
if (i + k < n) {
q = get_r(i + k);
}
ans = min(ans, 2 * p + l + 2 * q);
}
return ans;
}
