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)

import java.util.Scanner;

class Main {
  public static void main(String[] args) {
    Scanner stdInt = new Scanner(System.in);

  int l = 0;
  int[] ansans = new int[10000];
    while (true) {
      int n, x, ans = 0;

      n = stdInt.nextInt();
      x = stdInt.nextInt();
      if (n == 0 && x == 0) break;

      for (int i = n; i > 0; i--) {
        for (int j = i-1; j > 0; j--) {
          for (int k = j-1; k > 0; k--) {
            if (i + j + k == x) 
            ans++;
          }
        }
      }
      ansans[l++] = ans;
    }

    for (int i = 0; i < l; i++) {
      System.out.println(ansans[i]);
    }
  }
}