#include "boxes.h"
#include <bits/stdc++.h>
using namespace std;
#define SZ(v) ((int)(v).size())
#define ALL(v) (v).begin(),(v).end()
#define one first
#define two second
typedef long long ll;
typedef pair<double, double> pd;
typedef pair<int, int> pi;
typedef pair<ll, int> pli;
typedef pair<ll, ll> pll; typedef pair<ll, pi> plp;
typedef tuple<int, int, int> ti; typedef tuple<ll, int, int> tli;
const int INF = 0x3f2f1f0f;
const ll LINF = 1ll * INF * INF * 2;
const int MAX_N = 1e7 + 100;
int N, K, L, P[MAX_N];
ll Ls[MAX_N], Rs[MAX_N];
deque<int> Ps;
ll delivery(int n, int k, int l, int p[]) {
N = n; K = k; L = l;
for(int i=0; i<N; i++) Ps.push_back(p[i]);
while(SZ(Ps) > 0 && Ps.front() == 0) Ps.pop_front();
for(int i=0; i<SZ(Ps); i++) P[i+1] = Ps[i];
N = SZ(Ps);
P[0] = 0; P[N+1] = L;
for(int i=1; i<=N; i++) {
int ix = max(0, i-K);
Ls[i] = Ls[ix] + P[i] + min(P[i], L-P[i]);
}
for(int i=N; i>=1; i--) {
int ix = min(N+1, i+K);
Rs[i] = Rs[ix] + L-P[i] + min(P[i], L-P[i]);
}
ll ans = LINF;
for(int i=0; i<=N; i++) {
ans = min(ans, Ls[i] + Rs[i+1]);
// printf("%d : %lld %lld\n", i, Ls[i], Rs[i+1]);
}
return ans;
}
