#include "boxes.h"
#include <iostream>
using namespace std;
long long ll(int a)
{
return (long long)(a);
}
//#teams, capacity, #sections, position of each team
long long delivery(int N, int K, int L, int positions[])
{
long long dp_inc[N]; //minimum time needed to cover all 0, 1, ... i and end up at positions[i]
dp_inc[0] = ll(positions[0]);
for(int i = 1; i < K; i++)
{
dp_inc[i] = positions[i];
}
for(int i = K; i < N; i++)
{
dp_inc[i] = dp_inc[i - K] + ll(positions[i - K]) + ll(positions[i]);
}
// for(int i = 0; i < N; i++) cout << dp_inc[i] << ' ';
// cout << '\n';
long long dp_dec[N];
dp_dec[N-1] = L - positions[N-1];
for(int i = N-2; i > N-K-1; i--)
{
dp_dec[i] = L - positions[i];
}
for(int i = N-K-1; i >= 0; i--)
{
dp_dec[i] = dp_dec[i + K] + ll(L - positions[i + K]) + ll(L - positions[i]);
}
long long res = ll(1000 * 1000 * 1000) * ll(1000 * 1000 * 1000);
for(int i = 0; i < N-1; i++)
res = min(res, dp_inc[i] + ll(min(positions[i], L - positions[i])) + dp_dec[i+1] + ll(min(positions[i+1], L - positions[i+1])));
res = min(res, dp_inc[N-1] + ll(min(positions[N-1], L - positions[N-1])));
res = min(res, dp_dec[0] + ll(min(positions[0], L - positions[0])));
return res;
}
