#include <bits/stdc++.h>
#include "boxes.h"
using namespace std;
const long long INF = 2e18;
struct MinQue{
deque<long long> dque;
void clear(){
dque.clear();
}
void push(long long x){
while(!dque.empty() && dque.back() > x) dque.pop_back();
dque.push_back(x);
}
void pop(long long x){
assert(!dque.empty());
if(dque.front() == x) dque.pop_front();
}
long long getmin(){
assert(!dque.empty());
return dque.front();
}
};
long long delivery(int n, int k, int l, int p[]){
long long arr[n + 2] = {}, prefix[n + 2] = {}, suffix[n + 2] = {};
for(int i = 1; i <= n; i++) arr[i] = p[i - 1];
MinQue que;
que.push(0);
for(int i = 1; i <= n; i++){
if(i - k - 1 >= 0) que.pop(prefix[i - k - 1] + arr[i - k - 1]);
prefix[i] = que.getmin() + arr[i];
que.push(prefix[i] + arr[i]);
}
arr[n + 1] = l;
que.clear();
que.push(0);
for(int i = n; i >= 1; i--){
if(i + k + 1 <= n + 1) que.pop(suffix[i + k + 1] + (l - arr[i + k + 1]));
suffix[i] = que.getmin() + (l - arr[i]);
que.push(suffix[i] + (l - arr[i]));
}
long long ans = INF;
for(int i = 0; i <= n; i++){
ans = min(ans, prefix[i] + min(arr[i], l - arr[i]) + suffix[i + 1] + min(arr[i + 1], l - arr[i + 1]));
}
return ans;
}
