//#pragma GCC optimize("O3")
//#pragma GCC target("tune=native")
//#pragma GCC optimize("O3,unroll-loops")
//#pragma GCC target("avx2,bmi,bmi2,lzcnt,popcnt")
#include "boxes.h"
#include<iostream>
#include<vector>
#include<queue>
#include<deque>
#include<string>
#include<fstream>
#include<algorithm>
#include <iomanip>
#include<map>
#include <set>
#include <unordered_map>
#include <stack>
#include <unordered_set>
#include <cmath>
#include <cstdint>
#include <cassert>
//#include <ext/pb_ds/assoc_container.hpp>
//#include <ext/pb_ds/tree_policy.hpp>
#define shit short int
#define ll long long
//#define int ll
#define For(i, n) for(int i = 0; i < (int)n; i++)
#define ffor(i, a, n) for(int i = (int)a; i < (int)n; i++)
#define rfor(i, n) for(int i = (int)n; i >= (int)0; i--)
#define rffor(i, a, n) for(int i = (int)n; i >= (int)a; i--)
#define vec vector
#define ff first
#define ss second
#define pb push_back
#define pii pair<int, int>
#define NEK 2000000000
#define mod 1000000007
#define mod2 1000000009
#define rsz resize
#define prv1 47
#define prv2 43
#define D 8
#define trav(a,x) for (auto& a: x)
#define pb push_back
#define ub upper_bound
#define lb lower_bound
#define all(x) (x).begin(), (x).end()
#define sig 0.0000001
using namespace std;
//using namespace __gnu_pbds;
//template <typename T1, typename T2>
//using indexed_set = tree<pair<T1, T2>, null_type, less<pair<T1, T2>>, rb_tree_tag, tree_order_statistics_node_update>;
int delivery(int n, int k, int l, int positions[]) {
vec<int> a, b;
For(i, n) {
if (positions[i] <= l / 2) {
a.push_back(positions[i]);
}
else b.push_back(l - positions[i]);
}
sort(all(a)); sort(all(b));
vec<int> dp1(a.size() + 1, 0);
vec<int> dp2(b.size() + 1, 0);
For(i, a.size()) {
if (i + 1 - k < 0) dp1[i + 1] = 2*a[i];
else dp1[i + 1] = dp1[i + 1 - k] + 2*a[i];
}
For(i, b.size()) {
if (i + 1 - k < 0) dp2[i + 1] = 2*b[i];
else dp2[i + 1] = dp2[i + 1 - k] + 2*b[i];
}
//bez otocky
int mini = dp1[a.size()] + dp2[b.size()];
//s otockou
int as = a.size(), bs = b.size();
For(i, k + 1) {
int x, y;
if (as - i >= 0) {
x = dp1[as - i];
}
else {
x = 0;
}
if ((bs - (k - i)) >= 0) {
y = dp2[bs - (k - i)];
}
else {
y = 0;
}
mini = min(mini, x + y + l);
}
return mini;
}
/*
signed main() {
ios_base::sync_with_stdio(false); cin.tie(NULL);
int n, k, l; cin >> n >> k >> l;
int p[100];
For(i, n) cin >> p[i];
cout << delivery(n, k, l, p) << '\n';
return 0;
}*/
