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 && $x == 0) break;
    echo cnt($n,$x)."\n";
}
function cnt($n,$x){
    $cnt = 0;
    for($i = 1; $i <= $n-2; $i++){
        for($j = $i+1; $j <= $n-1; $j++){
            for($k = $j+1; $k <= $n; $k++){
                if(($i + $j + $k) == $x) $cnt++; 
            }
        }
    }
    return $cnt;
}