#include "boxes.h"
#include<bits/stdc++.h>
using namespace std ;
#define maxn 200009
#define ll long long
#define pb push_back
#define fi first
#define se second
#define left id<<1
#define right id<<1|1
#define re exit(0);
#define _lower(x) lower_bound(v.begin(),v.end(),x)-v.begin()+1
#define TIME ( 1.0*clock() / CLOCKS_PER_SEC )
const int mod = 1e9+7 ;
const int INF = 1e9 ;
typedef vector<int> vi ;
typedef pair<int,int> pii ;
typedef vector<pii> vii ;
template < typename T > void chkmin ( T &a , T b ) { if ( a > b ) a = b ; }
template < typename T > void chkmax ( T &a , T b ) { if ( a < b ) a = b ; }
void add ( int &a , int b )
{
a += b ;
if ( a >= mod ) a -= mod ;
if ( a < 0 ) a += mod ;
}
int n , k , L ;
int p [maxn] ;
ll dp [maxn] ;
bool in_right ( int pos )
{
return ( pos >= (L+1)/2 ) ;
}
long long delivery(int _N, int _K, int _L, int _p[]) {
n = _N , k = _K , L = _L ;
for ( int i = 1 ; i <= n ; i ++ ) p [i] = _p [i-1] ;
int pos = -1 ;
for ( int i = 1 ; i <= n ; i ++ )
{
if ( in_right (p[i]) )
{
pos = i ;
break ;
}
dp [i] = dp [max(0,i-k)] + p [i] ;
}
for ( int i = n ; in_right (i) ; i -- ) dp [i] = dp [min(n+1,i+k)] + L - p [i] ;
ll res = 1e18 ;
for ( int i = 1 ; i <= n ; i ++ )
{
if ( i + k - 1 < pos ) continue ;
if ( i + k - 1 > n || i >= pos ) break ;
res = min (res,2*dp[i-1]+2*dp[i+k]+L) ;
}
return res;
}
