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 JAVA (judge verdict: Accepted)

public class Main{
  public void run(java.io.InputStream in, java.io.PrintStream out){
    java.util.Scanner sc = new java.util.Scanner(in);
/*answer*/
    int n, x;
    int i, j, k, count;

    for(;;){
      n = sc.nextInt();
      x = sc.nextInt();
      if(n == 0 && x == 0)break;

      count = 0;
      for(i = 1;i <= n;i++){
        for(j = i + 1;j <= n;j++){
          if(x - i - j > j && x - i - j <= n)count++;
        }
      }

      System.out.println(count);
    }


    sc.close();
  }
  public static void main(String[] args){
    (new Main()).run(System.in, System.out);
  }
}