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 Python3 (judge verdict: Accepted)

while True:
    (n, x) = [int(i)for i in input().split()]
    if n == x == 0:
        break

    count = 0
    for a in range(1, n + 1 - 2):
        for b in range(a + 1, n + 1 - 1):
            for c in range(b + 1, n + 1):
                if (a + b + c) == x:
                    count += 1
    print(count)