#include "boxes.h"
#include <bits/stdc++.h>
//#include <ext/pb_ds/assoc_container.hpp>
//#include <ext/pb_ds/tree_policy.hpp>
//#include "bits_stdc++.h"
#define f first
#define s second
#define pb push_back
#define mp make_pair
#define lb lower_bound
#define ub upper_bound
#define input(x) scanf("%ld", &x);
#define input2(x, y) scanf("%lld%lld", &x, &y);
#define input3(x, y, z) scanf("%lld%lld%lld", &x, &y, &z);
#define input4(x, y, z, a) scanf("%ld%ld%ld%ld", &x, &y, &z, &a);
#define print(x, y) printf("%ld%c", x, y);
#define show(x) cerr << #x << " is " << x << endl;
#define show2(x,y) cerr << #x << " is " << x << " " << #y << " is " << y << endl;
#define show3(x,y,z) cerr << #x << " is " << x << " " << #y << " is " << y << " " << #z << " is " << z << endl;
#define discretize(x) sort(x.begin(), x.end()); x.erase(unique(x.begin(), x.end()), x.end());
using namespace std;
//using namespace __gnu_pbds;
//#define ordered_set tree<int, null_type, less<int>, rb_tree_tag, tree_order_statistics_node_update>
//#define ordered_multiset tree<int, null_type, less_equal<int>, rb_tree_tag, tree_order_statistics_node_update>
typedef long long ll;
typedef long double ld;
typedef pair<ld, ll> pd;
typedef pair<string, ll> psl;
typedef pair<ll, ll> pi;
typedef pair<ll, pi> pii;
long long delivery(int N, int K, int L, int p[])
{
ll ans = LLONG_MAX;
ll n= N, k = K, l= L;
ll dpl[N+1], dpr[N+1];
dpr[n] = 0; dpl[0] = 0;
for (ll i=1; i<=n; ++i)
{
if (i-k<1) dpl[i] = p[i-1]*2;
else dpl[i] = p[i-1]*2 + dpl[i-k];
}
for (ll i=n; i>=1; --i)
{
if (i+k>n) dpr[i] = (l-p[i-1])*2;
else dpr[i] = (l-p[i-1])*2 + dpr[i+k];
}
// choose only one side
ans = min(dpl[n], dpr[1]);
// choose 1 cycle
for (ll i=k; i<=n; ++i) ans = min(ans, dpl[i-k] + dpr[i+1] + l);
if (n<=k) ans = min(ans, l);
// choose 0 cycle
for (ll i=1; i<n; ++i) ans = min(ans, dpl[i] + dpr[i+1]);
return ans;
}
