#include "boxes.h"
#include "bits/stdc++.h"
#define rep(i, n) for(ll i = 0; i < ll(n); ++i)
#define rep2(i, s, n) for(ll i = ll(s); i < ll(n); ++i)
#define rrep(i, n) for(ll i = ll(n)-1; i >= 0; --i)
#define pb push_back
#define eb emplace_back
#define all(a) a.begin(),a.end()
#define SZ(a) int(a.size())
using namespace std;
using ll = long long;
using P = pair<int, int>;
using vi = vector<int>;
using vvi = vector<vi>;
using vl = vector<ll>;
using vvl = vector<vl>;
using vp = vector<P>;
using vvp = vector<vp>;
using vb = vector<bool>;
using vvb = vector<vb>;
using vs = vector<string>;
const int inf = 1001001001;
const ll linf = 1001001001001001001;
template<class T>
bool chmin(T &a, T b) {
if (a > b) {
a = b;
return true;
}
return false;
}
template<class T>
bool chmax(T &a, T b) {
if (a < b) {
a = b;
return true;
}
return false;
}
ll delivery(int n, int k, int l, int p[]) {
vl a, b;
a.pb(0);
rep(i, n) {
if (p[i] <= l / 2) a.pb(p[i]);
else b.pb(l - p[i]);
}
b.pb(0);
reverse(all(b));
rep(i, SZ(a)) {
a[i] *= 2;
if (i >= k) a[i] += a[i - k];
}
rep(i, SZ(b)) {
b[i] *= 2;
if (i >= k) b[i] += b[i - k];
}
ll ans = a.back() + b.back();
ll mx = max(0LL, ans - ll(n + k - 1) / k * l);
for (ll &i: a) i = a.back() - i;
for (ll &i: b) i = b.back() - i;
reverse(all(a));
reverse(all(b));
rep(i, SZ(a)) rep(j, SZ(b)) {
chmax(mx, a[i] + b[j] - ll(i + j + k - 1) / k * l);
}
//// rep(i, SZ(a) - 2 * k) assert(a[i + k] - a[i] >= a[i + 2 * k] - a[i + k]);
//// rep(i, SZ(b) - 2 * k) assert(b[i + k] - b[i] >= b[i + 2 * k] - b[i + k]);
// rep(sa, k + 1) {
// int sb = k - sa;
// if (sa >= SZ(a) or sb >= SZ(b)) continue;
// ll now = a[sa] + b[sb] - l;
// chmax(mx, now);
// while (sa + k < SZ(a) or sb + k < SZ(b)) {
// if (sa + k < SZ(a) and sb + k < SZ(b)) {
// if (a[sa + k] - a[sa] > b[sb + k] - b[sb]) {
// now += a[sa + k] - a[sa] - l;
// sa += k;
// } else {
// now += b[sb + k] - b[sb] - l;
// sb += k;
// }
// } else if (sa + k < SZ(a)) {
// now += a[sa + k] - a[sa] - l;
// sa += k;
// } else {
// now += b[sb + k] - b[sb] - l;
// sb += k;
// }
// chmax(mx, now);
// }
// }
return ans - mx;
}
