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) {
    fscanf(STDIN, '%d %d', $n, $x);
    if (isEnd($n, $x)) { break; };

    $count = 0;
    for ($i = 1; $i < ($x / 3); $i++) {
        for ($j = $i + 1; $j < (($x - $i) / 2); $j++) {
            $remainder = $x - ($i + $j);
            if ($n < $remainder || $remainder <= $j) { continue; }

            $count++;
        }
    }
    $result[] = $count;
}

echo implode(PHP_EOL, $result), PHP_EOL;

function isEnd($n, $x)
{
    return !($n || $x);
}