#include "boxes.h"
#include <set>
#define MAXN 10000000
using namespace std;
long long dp1[MAXN + 5]; // clockwise, 1 based
long long dp2[MAXN + 5]; // counterclockwise
long long delivery(int N, int K, int L, int p[]) {
dp1[0] = 0;
for (int i = 1; i <= N; i++) { // to the left
int prev = max(0, i - K);
dp1[i] = dp1[prev] + min(L - p[i - 1], p[i - 1]); // prev here refers to team before the K
if (prev == 0) {
dp1[i] += p[i - 1];
}
else {
dp1[i] += p[i - 1] - p[prev] + min(L - p[prev], p[prev]); // prev here refers to part of the K
}
}
dp2[N+1] = 0;
for (int i = N; i >=0; i--) { // to the right
int prev = min(N + 1, i + K);
dp2[i] = dp2[prev] + min(L - p[i - 1], p[i - 1]);
if (prev == N + 1) {
dp2[i] += L - p[i - 1];
}
else {
dp2[i] += p[prev - 2] - p[i - 1] + min(L - p[prev - 2], p[prev - 2]);
}
}
long long ans = 10e16;
for (int i = 0; i <= N; i++) {
ans = min(ans, dp1[i] + dp2[i + 1]);
}
return ans;
}
