#include <bits/stdc++.h>
#include "boxes.h"
using namespace std;
//#define int long long
#define OYY LLONG_MAX
#define faster ios_base::sync_with_stdio(false);cin.tie(NULL);cout.tie(NULL);
#define fi first
#define se second
#define FOR for(int i=1;i<=n;i++)
#define mid (start+end)/2
#define pb push_back
#define lim 200005
typedef long long lo;
lo dp1[lim],dp2[lim];
long long delivery(int N, int K, int L, int p[]) {
lo cev=LLONG_MAX;
for(int i=1;i<=N;i++){// baştan
int l=max(0,i-K);
dp1[i]=(lo)dp1[l]+p[i-1]+min(p[i-1],L-p[i-1]);
}
for(int i=N;i>=1;i--){
int r=min(N+1,i+K);
dp2[i]=(lo)dp2[r]+L-p[i-1]+min(p[i-1],L-p[i-1]);
}
for(int i=1;i<=N;i++){
//cout<<dp1[i]<<" "<<dp2[i]<<endl;
cev=min(cev,dp1[i]+dp2[i+1]);
}
return cev;
}
//~ int main(){
//~ faster
//~ int n,k,l;
//~ cin>>n>>k>>l;
//~ int dizi[n];
//~ for(int i=0;i<n;i++)cin>>dizi[i];
//~ cout<<delivery(n,k,l,dizi)<<'\n';
//~ return 0;
//~ }
