#include "boxes.h"
#include<bits/stdc++.h>
using namespace std;
long long n , k , l , a [10000007] , b [10000007] , adp [10000007] , bdp [10000007];
long long delivery(int N, int K, int L, int p[]) {
n = N , k = K , l = L;
for ( int i = 1 ; i <= n + 1 ; i ++ )
{
adp [i] = 1e18;
bdp [i] = 1e18;
if ( i != n + 1 )
{
a [i] = p [ i - 1 ];
b [i] = a [i];
}
}
long long ans = 1e18;
multiset < long long > ms;
ms . insert ( 0 );
for ( int i = 1 ; i <= n ; i ++ )
{
adp [i] = min ( adp [i] , * ms . begin () + 2 * a [i] );
ms . insert ( adp [i] );
if ( i - k >= 0 ) ms . erase ( ms . lower_bound ( adp [ i - k ] ) );
}
reverse ( a + 1 , a + n + 1 );
ms . clear ();
ms . insert ( 0 );
for ( int i = 1 ; i <= n ; i ++ )
{
bdp [i] = min ( bdp [i] , * ms . begin () + 2 * ( l - a [i] ) );
ms . insert ( bdp [i] );
if ( i - k >= 0 ) ms . erase ( ms . lower_bound ( bdp [ i - k ] ) );
}
for ( int i = 0 ; i <= n ; i ++ )
{
ans = min ( ans , adp [i] + bdp [ n - i ] );
}
return ans;
}
