#include "boxes.h"
// author : sentheta aka vanwij
#include<iostream>
#include<iomanip>
#include<algorithm>
#include<cassert>
#include<random>
#include<chrono>
#include<cmath>
#include<string>
#include<vector>
#include<bitset>
#include<queue>
#include<stack>
#include<map>
#include<set>
using namespace std;
#define Int long long
#define V vector
#define pii pair<int,int>
#define ff first
#define ss second
mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());
#define pow2(x) (1LL<<(x))
#define msb(x) (63-__builtin_clzll(x))
#define bitcnt(x) (__builtin_popcountll(x))
#define nl '\n'
#define _ << ' ' <<
#define all(x) (x).begin(), (x).end()
#define rep(i,a,b) for(int i = (int)(a); i < (int)(b); i++)
#define dbg(x) if(1) cout << "?" << #x << " : " << (x) << endl << flush;
const Int INF = 1e18;
const Int N = 1e7+5;
Int n, k, len;
int *p;
V<Int> v[2];
Int dp[2][N];
Int b[N];
Int delivery(int _n,int _k,int _l,int _p[]) {
n = _n; k = _k; len = _l; p = _p;
v[0] = v[1] = {0};
Int nonzro = 0;
rep(i,0,n) if(p[i]){
nonzro++;
if(p[i]<=len/2) v[0].push_back(p[i]);
else v[1].push_back(len-p[i]);
}
rep(t,0,2) sort(all(v[t]));
// dbg(nonzro);
if(nonzro <= k){
Int ans = 0;
rep(t,0,2) if(!v[t].empty()) ans += v[t].back()*2;
ans = min(ans, len);
return ans;
}
rep(i,0,k){
b[i] = INF;
}
Int ans = INF;
rep(t,0,2){
// dbg(t);
rep(i,0,v[t].size()){
// dbg(v[t][i]);
dp[t][i] = v[t][i]*2;
if(i >= k){
dp[t][i] += dp[t][i-k];
}
// dbg(dp[t][i]);
if(t==0){
b[i%k] = min(b[i%k], dp[t][i]*k-i*len);
// dbg(b[i%k]);
}
if(t==1){
Int mov = b[(nonzro-i)%k] + dp[t][i]*k-i*len +nonzro*len;
mov /= k;
// dbg(mov);
ans = min(ans, mov);
}
// cout << nl;
}
}
// dbg(b[0]);
// dbg(dp[1][0]);
return ans;
}
