题目描述
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.
Examples
Input
3 2
Output
9
Input
5 3
Output
1
Input
31415 9265
Output
27
Input
35897 932
Output
114191
输入格式
见题面
输出格式
见题面
样例输入
31415 9265
样例输出
27