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 Julia (0.5.0) (judge verdict: Time Limit Exceeded)

function main()
  x = parse.(split(readline()))
  count = 0
  for i in 1:x[1]
    for j in 1:x[1]
      for k in 1:x[1]
        if (i+j)%x[2] == 0 && (j+k)%x[2] == 0 && (k+i)%x[2] == 0
          count += 1
        end
      end
    end
  end
  print(count)
end

main()