Problem Statement

Given are integers N and K.
How many quadruples of integers (a,b,c,d) satisfy both of the following conditions?

• $1 \leq a,b,c,d \leq N$
• a+b-c-d=K

Input

Input is given from standard input in the following format:
N K

Output

Print the answer.

Constraints

• $1 \leq N \leq 10^5$
• -$2(N-1) \leq K \leq 2(N-1)$
• All numbers in input are integers.

Sample Input 1

2 1

Sample Output 1

4

Four quadruples below satisfy the conditions:

• (a,b,c,d)=(2,1,1,1)
• (a,b,c,d)=(1,2,1,1)
• (a,b,c,d)=(2,2,2,1)
• (a,b,c,d)=(2,2,1,2)

Sample Input 2

2525 -425

Sample Output 2

10314607400

见题面 Input 部分

见题面 Output 部分