#include "bits/stdc++.h"
#include "boxes.h"
using namespace std;
using ll = long long;
using ld = long double;
using ull = unsigned long long;
mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());
// https://codeforces.com/blog/entry/79148
class Timer: chrono::high_resolution_clock {
const time_point start_time;
public:
Timer(): start_time(now()) {}
rep elapsed_time() const {
return chrono::duration_cast<chrono::milliseconds>(now() - start_time).count();
}
} timer;
ll delivery(int n, int k, int l, int v[]) {
vector<ll> dp(n, 1e18);
auto dist = [&] (ll x, ll y) {
if (x > y) {
swap(x, y);
}
return min(y - x, l - y + x);
};
auto trip = [&] (int lb, int rb) {
ll cur;
if (((l & 1) && v[lb] <= l / 2 && v[rb] > l / 2) || (!(l & 1) && v[lb] < l / 2 && v[rb] > l / 2)) {
cur = l;
}
else {
cur = min(ll(l), 2 * max(dist(0, v[lb]), dist(0, v[rb])));
}
if (!lb) {
dp[rb] = min(dp[rb], cur);
}
else {
dp[rb] = min(dp[rb], dp[lb - 1] + cur);
}
};
int nxt = n;
for (int i = 0; i < n - 1; i++) {
if (v[i + 1] - v[i] > l / 2) {
nxt = i + 1;
break;
}
}
for (int i = 0; i < nxt % k; i++) {
trip(0, i);
}
for (int i = nxt % k; i < nxt; i++) {
if (i >= k - 1) {
trip(i - k + 1, i);
}
trip(i - (nxt % k) + 1, i);
}
for (int i = nxt; i < nxt + ((n - nxt) % k); i++) {
trip(nxt, i);
}
for (int i = nxt + ((n - nxt) % k); i < n; i++) {
if (i - k + 1 >= nxt) {
trip(i - k + 1, i);
}
trip(i - ((n - nxt) % k) + 1, i);
}
if (nxt != n) {
return dp[n - 1] + dp[nxt - 1];
}
return dp[n - 1];
}
