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)

/**
  * http://judge.u-aizu.ac.jp/onlinejudge/description.jsp?id=ITP1_7_B
  * Structured Program II - How many ways?
  */
object Main {
  def main(args: Array[String]): Unit = {
    Iterator.continually(io.StdIn.readLine()).takeWhile(_ != null).map(_.split(" ").map(_.toInt))
      .map { case Array(n, x) => (n, x) }
      .takeWhile(_ != (0, 0))
      .toList
      .map { case (n, x) =>
        (1 to n).combinations(3).count(_.sum == x)
      }
      .foreach(println)
  }
}