Problem:
Score : 300 points

Problem Statement

You are given integers N and K. Find the number of triples (a,b,c) of positive integers not greater than N such that a+b,b+c and c+a are all multiples of K.
The order of a,b,c does matter, and some of them can be the same.

Constraints

1 \leq N,K \leq 2\times 10^5

N and K are integers.

Input

Input is given from Standard Input in the following format:

N K

Output

Print the number of triples (a,b,c) of positive integers not greater than N such that a+b,b+c and c+a are all multiples of K.

Sample Input 1

3 2

Sample Output 1

9

(1,1,1),(1,1,3),(1,3,1),(1,3,3),(2,2,2),(3,1,1),(3,1,3),(3,3,1) and (3,3,3) satisfy the condition.

Sample Input 2

5 3

Sample Output 2

1

Sample Input 3

31415 9265

Sample Output 3

27

Sample Input 4

35897 932

Sample Output 4

114191

Solution in Java8 (OpenJDK 1.8.0) (judge verdict: Wrong Answer)

import java.util.*;

class Main{
  public static void main(String args[]){
    Scanner scan = new Scanner(System.in);
    int n = scan.nextInt();
    int k = scan.nextInt();
    int sum = 0;
    int[] amari1 = new int[2];
    int amari;
    int a;
    int b;
    int c=1;
    /*for(int i = 1;i <= n;i++){
      amari = i%k;
      if(amari1[amari] == 1){
        for(int l=0;l < k;l++){
          c +=amari1[l];
        }
        if(c == k){
          break;
        }
        c = 0;
        continue;
      }else{
        amari1[amari] = 1;
        a = (n - amari)/k;
        b = (n -(k-amari))/k;
        sum += a*a*b*2;
      }
    }*/

    if(k == (k/2)*2){
      amari1[0] = 0;
      amari1[1] = k/2;
      c=2;
    }
    for(int l = 0;l < c;l++){
    a = (n+amari1[l])/k;
    sum += (a*a*a );
  }

    System.out.println(sum);


  }
}