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]){
    val sc=new java.util.Scanner(System.in)
    val b=new scala.util.control.Breaks
    b.breakable{
      while(true){
        val n,x=sc.nextInt()
        if(n==0) b.break
        var ans=0
        for(i<-1 to n;j<-i+1 to n;k<-j+1 to n if i+j+k==x) ans+=1
        println(ans)
      }
    }
  }
}