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 extends App {

  while (true) {
    val Array(n, x) = scala.io.StdIn.readLine.split(" ").map(_.toInt)

    if (n == 0 && x == 0) {
      sys.exit()
    }
    var count = 0
    for (a <- 1 to n; b <- a + 1 to n; c <- b + 1 to n if a + b + c == x) {
      count += 1
    }
    println(count)
  }

}