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: Time Limit Exceeded)

N, K = [int(nk) for nk in input().split()]

ans = 0
# a+b=pK b+c=qK c+a=rK
for p in range(1, ((2*N)//K)+1):#1<=p<=(2*N)//K
  for q in range(1, ((2*N)//K)+1):
    for r in range(1, ((2*N)//K)+1):
      a = (( p-q+r)*K)/2
      b = (( p+q-r)*K)/2
      c = ((-p+q+r)*K)/2
      if b < 1:
        break
      elif a > N or c > N:
        break
      elif b > N:
        continue
      elif a < 1 or c < 1:
        continue
      elif a == int(a) and b == int(b) and c == int(c):
        ans += 1
        
print(ans)