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 PHP (judge verdict: Accepted)

<?php
while (true){
    list($n, $x) = explode(" ", trim(fgets(STDIN)));
    if ($n == 0 && $x == 0) {
        break;
    }
    $count = 0;
    for ($first_num = 1; $first_num <= $n; $first_num++) {
        for ($second_num = $first_num + 1; $second_num <= $n; $second_num++) {
            for ($third_num = $second_num + 1; $third_num <= $n; $third_num++) {
                if ($first_num + $second_num + $third_num == $x) {
                   $count++;
                }
            }
        }
    }
echo $count. PHP_EOL;
}