#include<bits/stdc++.h>
#include "boxes.h"
using namespace std;
#define int long long
#define FOR(i, a, b) for (int i = (a), _b = (b); i <= _b; i++)
#define FORD(i, a, b) for (int i = (a), _b = (b); i >= _b; i--)
#define fi first
#define se second
#define pb push_back
#define ALL(a) (a).begin(), (a).end()
#define task "kbsiudthw"
typedef vector<int> vi;
typedef pair<int, int> ii;
typedef pair<int, ii> pii;
const int N = 1e5 + 5;
const int INF = 0x3f3f3f3f;
const int MOD = 1e9 + 2277;
long long delivery(int32_t N, int32_t K, int32_t L, int32_t p[]) {
vector<vector<long long>> dp(2, vector<long long>(N + 5, 0));
deque<int> dq;
dq.push_back(1);
FOR (i, 1, N){
while (dq.front() + K < i) dq.pop_front();
dp[0][i] = dp[0][dq.front()] + min(L, p[i-1] * 2);
while (!dq.empty() && dp[0][dq.back()] >= dp[0][i]) dq.pop_back();
dq.push_back(i);
}
dq.clear(); dq.pb(N+1);
FORD(i, N, 1){
while (dq.front() - K > i) dq.pop_front();
dp[1][i] = dp[1][dq.front()] + min(L, (L - p[i-1]) * 2);
while (!dq.empty() && dp[1][dq.back()] >= dp[1][i]) dq.pop_back();
dq.push_back(i);
}
long long ans = 1e18;
FOR (i, 0, N) ans = min(ans, dp[0][i] + dp[1][i+1]);
return ans;
}
//signed main(){
// ios_base::sync_with_stdio(0);
// cin.tie(0); cout.tie(0);
// if (fopen(task".inp", "r")){
// freopen(task".inp", "r", stdin);
// freopen(task".out", "w", stdout);
// }
// int p[] = {1, 2, 5};
// cout << delivery(3, 2, 8, p);
//
// return 0;
//}
