#include "boxes.h"
#include <vector>
#include <algorithm>
#include <map>
#include <iostream>
#define INF 1'000'000'000'000'000'000
#define ABS(a) ((a) > 0 ? (a) : -(a))
#define MIN(a, b) ((a) < (b) ? (a) : (b))
std::vector<long long> people;
long long l;
inline long long dist(long long curr, long long next = 0)
{
return MIN(ABS(people[curr] - people[next]), l - ABS(people[curr] - people[next]));
}
long long delivery(int N, int K, int L, int p[])
{
l = L;
people.resize(N+2);
people[0] = 0;
for (int i = 0; i < N; ++i)
people[i+1] = p[i];
people[N+1] = 0;
long long root[N+2]{};
long long next[N+2]{};
long long kDist[N+2]{};
for (int i = 0; i <= N; ++i)
root[i] = MIN(people[i], l - people[i]),
next[i] = MIN(ABS(people[i] - people[i+1]), l - ABS(people[i] - people[i+1]));
for (int i = 0; i <= N; ++i)
kDist[i] = (i+K-1 <= N ? people[i+K-1] : L) - people[i];
long long best = INF;
for (int i = 1; i <= K; ++i)
{
long long sum = 0;
int pos = 0;
sum += (pos+i <= N ? people[pos+i] : L) - people[pos];
pos += i;
while (pos <= N)
{
sum += root[pos];
sum += root[++pos];
sum += kDist[pos];
pos += K-1;
}
best = std::min(best, sum);
}
return best;
}
