#include <bits/stdc++.h>
#include "boxes.h"
#define x first
#define y second
#define all(v) v.begin(), v.end()
#define chkmin(a, b) a = min(a, b)
#define chkmax(a, b) a = max(a, b)
using namespace std;
typedef long long ll;
typedef vector<int> vi;
typedef vector<vi> vvi;
typedef pair<int, int> pii;
typedef vector<pii> vii;
const int MAX_N = 1e6 + 5;
const ll infinity = 1e18;
//struct Seg{
// vector<ll> seg;
// int n;
// Seg (int m) {
// for (n = 1; n < m; n <<= 1);
// seg.resize(2 * n);
// }
// void update(int i, int x) {
// seg[i += n] = x;
// for (i >>= 1; i; i >>= 1) seg[i] = min(seg[2 * i], seg[2 * i + 1]);
// }
// ll query(int l, int r) {
// ll ans = infinity;
// for (l += n, r += n; l < r; l >>= 1, r >>= 1) {
// if (l & 1) chkmin(ans, seg[l++]);
// if (r & 1) chkmin(ans, seg[--r]);
// }
// return ans;
// }
//};
int n, k, l;
ll dpl[MAX_N], dpr[MAX_N];
void CalcL(vi &p) {
vi d = {0};
d.reserve(n + 1);
int ind = 0;
for (int i = 1; i <= n; i++) {
while (d[ind] < i - k) ind++;
dpl[i] = dpl[d[ind]];
dpl[i] += min<ll>(l, 2 * p[i]);
while (!d.empty() && dpl[d.back()] > dpl[i]) d.pop_back();
d.push_back(i);
}
}
void CalcR(vi &p) {
vi d = {n + 1};
d.reserve(n + 1);
int ind = 0;
for (int i = n; i >= 0; i--) {
while (d[ind] > i + k) ind++;
dpr[i] = dpr[d[ind]];
dpr[i] += min<ll>(l, 2 * (l - p[i]));
while (!d.empty() && dpr[d.back()] > dpr[i]) d.pop_back();
d.push_back(i);
}
}
inline ll Solve(int ind) {
return dpl[ind - 1] + dpr[ind];
}
long long delivery(int N, int K, int L, int P[]) {
n = N, k = K, l = L;
vi p(n + 1);
ll ans = infinity;
for (int i = 1; i <= n; i++) p[i] = P[i - 1];
CalcL(p), CalcR(p);
for (int ind = 1; ind <= n + 1; ind++) {
chkmin(ans, Solve(ind));
}
return ans;
}
//3 2 8
//1 2 5
