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 Python (3.4.3) (judge verdict: Runtime Error)

count=0
index=k//2
while index<=n:
    a=index
    index2=0
    index+=1
    index2=k-a
    while index2<=n:
        b=index2
        if (a+b)%k!=0:
            index2+=1
        else:
            index3=k-a
            index2+=1
            while index3<=n:
                c=index3
                if(a+c)%k==0 and (b+c)%k==0:
                    if a==b and b==c:
                        count+=1
                    elif a!=b and b!=c and c!=a:
                        count+=6
                    else:
                        count+=3
                    index3+=1
                else:
                    pass
                    index3+=1
print(count)