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) {
    $answer = 0;
    $memo = [];
    $nums = explode(" ", trim(fgets(STDIN)));
    $max = $nums[0];
    $target = $nums[1];
    if ($max == 0 && $target == 0) break;

    for ($i = 1; $i <= $max; $i++) {
        for ($j = 1; $j <= $max; $j++) {
            for ($k = 1; $k <= $max; $k++) {
                if ($i + $j + $k == $target && !($i == $j || $j == $k || $i == $k)) {
                    $tmp = [$i, $j, $k];
                    sort($tmp);
                    if (in_array($tmp, $memo) === false) {
                        $memo[] = $tmp;
                        $answer++;
                    }
                }
            }
        }
    }
    echo $answer . "\n";
}