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 = {
    Iterator.continually {
      val Array(n, x, _*) = io.StdIn.readLine().split(" ").map(_.toInt)
      (n, x)
    }.takeWhile {
      case (0, 0) => false
      case _ => true
    }.foreach { case (n, x) =>
      val count =
        (1 to n - 2).map { i =>
          val v = x - i
          (i + 1 to n.min(v / 2)).count { j =>
            val pair = v - j
            j < pair && pair <= n
          }
        }.sum

      println(count)
    }
  }
}