Problem:
How many ways?

Write a program which identifies the number of combinations of three integers which satisfy the following conditions:

You should select three distinct integers from 1 to n.

A total sum of the three integers is x.

For example, there are two combinations for n = 5 and x = 9.

1 + 3 + 5 = 9

2 + 3 + 4 = 9

Input

The input consists of multiple datasets. For each dataset, two integers n and x are given in a line.

The input ends with two zeros for n and x respectively. Your program should not process for these terminal symbols.

Constraints

3 ≤ n ≤ 100

0 ≤ x ≤ 300

Output

For each dataset, print the number of combinations in a line.

Sample Input

5 9
0 0

Sample Output

2

Note

      解説

Solution in Scala (judge verdict: Accepted)

object Main {
  def main(args: Array[String]): Unit = {
    val scanner = new java.util.Scanner(System.in)

    while(true) {
      val n, x = scanner.nextInt
      if(n == 0 && x == 0) System.exit(0)
      println(search(n, x).filter(t => t._1.length == 3 && t._2 == x).length)
    }
  }

  def search(n: Int, x: Int): List[(List[Int], Int)] = {
    if(n == 1) {
      List((List(1), 1), (Nil, 0))
    } else {
      val l = search(n - 1, x)
      l.filter(_._1.length <= 3) ++ l.filter(t => t._1.length <= 2 && t._2 + n <= x).map(t => (n :: t._1, n + t._2))
    }
  }
}