#include "boxes.h"
#include <bits/stdc++.h>
using namespace std;
long long delivery(int n, int k, int l, int p[]) {
vector<long long> dp1(n);
for (int i = 0; i < n; i++) {
if (i < k) dp1[i] = p[i];
else dp1[i] = dp1[i - k] + min(p[i - k], l - p[i - k]) + p[i];
}
vector<long long> dp2(n);
for (int i = n - 1; i >= 0; i--) {
if (n - 1 - i < k) dp2[i] = l - p[i];
else dp2[i] = dp2[i + k] + min(p[i + k], l - p[i + k]) + l - p[i];
}
long long ans = 1e18;
for (int i = 0; i < n; i++) {
if (i + k + 1 < n) {
ans = min(ans, dp1[i] + min(p[i], l - p[i]) + l + dp2[i + k] + min(p[i + k + 1], l - p[i + k + 1]));
}
if (i + 1 < n) {
ans = min(ans, dp1[i] + min(p[i], l - p[i]) + dp2[i + 1] + min(p[i + 1], l - p[i + 1]));
}
}
ans = min(ans, dp1[n - 1] + min(p[n - 1], l - p[n - 1]));
ans = min(ans, dp2[0] + min(p[0], l - p[0]));
return ans;
}
