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: Memory Limit Exceeded)

import java.util.Scanner

object HowManyWays {
  val sc = new Scanner(System.in)
  var n = 0
  var x = 0

  def input()  {
    n = sc.nextInt()
    x = sc.nextInt()
    // println("n = " + n)
    // println("x = " + x)
  }
  def listProduct(): Int = {
    val a = List.range(1, n + 1)
    // println(a)
    val b = a.combinations(3).map(l => l.sum).toList

    val c = b.count(p => p == x)
    // println(c)
    c
  }
  def run: Unit = {
    input()
    while (n != 0 || x != 0) {
      println( listProduct() )
      input()
    }
  }
}
object Main extends App{
  HowManyWays.run

}