// looking to shine brighter in this world...
#define TASK "boxes"
#include "boxes.h"
#ifdef LOCAL
#include "local.h"
#else
#include <bits/stdc++.h>
#define debug(...)
#define DB(...)
#endif
using namespace std;
using ll = long long;
using ld = long double;
#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(), x.rend()
#define fi first
#define se second
#define For(i, l, r) for (int i = (l); i <= (r); ++i)
#define Ford(i, r, l) for (int i = (r); i >= (l); --i)
#define Rep(i, n) For (i, 0, (n) - 1)
#define Repd(i, n) Ford (i, (n) - 1, 0)
#define Fe(...) for (auto __VA_ARGS__)
template <class C> inline int isz(const C& c) { return static_cast<int>(c.size()); }
template <class T> inline bool chmin(T& a, const T& b) { return (a > b) ? a = b, true : false; }
template <class T> inline bool chmax(T& a, const T& b) { return (a < b) ? a = b, true : false; }
const bool __initialization = []() {
cin.tie(nullptr)->sync_with_stdio(false);
if (fopen(TASK".inp", "r")) {
(void)(!freopen(TASK".inp", "r", stdin));
(void)(!freopen(TASK".out", "w", stdout)); }
cout << setprecision(12) << fixed;
return true;
}();
constexpr ld eps = 1e-9;
constexpr int inf = 1e9;
constexpr ll linf = 1e18;
// =============================================================================
constexpr int maxn = 1e7 + 5;
ll pref[maxn];
ll suff[maxn];
long long delivery(int n, int k, int l, int p[]) {
Rep (i, n) {
if (i < k) {
pref[i] = min(l, 2 * p[i]);
}
else {
pref[i] = min(l, 2 * p[i]) + pref[i - 1];
}
}
Repd (i, n) {
if (n - i - 1 < k) {
suff[i] = min(l, 2 * (l - p[i]));
}
else {
suff[i] = min(l, 2 * (l - p[i])) + suff[i + 1];
}
}
ll ans = min(pref[n - 1], suff[0]);
Rep (i, n - 1) {
chmin(ans, pref[i] + suff[i + 1]);
}
return ans;
}
