Background

AtCoder Regular Contest 102-C 你要尽量多看英语

Description

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.

你得到了整数N和K。求不大于N的正整数的三元组（a，b，c）的个数，使得a+b，b+c和c+a都是K的倍数。a，b、c的顺序很重要，其中一些可以是相同的。

Constraints

• 1≤N,K≤2×10^5
• N and Kare integers.

Format

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+aare all multiples of K.

Samples

3 2

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.

5  3

1

31415 9265

27

31415 9265

114191