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 JavaScript (judge verdict: Accepted)

function Main(input) {
    input = input.split("\n");
    for (i=0; i<input.length; i++) {
        tmp = input[i].split(" ")
        var n = parseInt(tmp[0])
        var x = parseInt(tmp[1])
        var num = 0
        if (n === 0 && x === 0) {
            break;
        }
        for (j=1; j <= n-2; j++) {
            for (k=j+1; k<=n-1; k++) {
                for (l=k+1; l<= n; l++) {
                    if (j + k + l === x) {
                        num += 1
                    }
                }
            }
        }
        console.log(num)
    }
}

Main(require("fs").readFileSync("/dev/stdin", "utf8"));