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 Python (judge verdict: Accepted)

while 1:
    n, x = map(int, raw_input().split())
    if n == 0 and x == 0: break

    count = 0
    for i in range(1, n+1):
        for j in range(i+1, n+1):
            for k in range(j+1, n+1):
                if i + j + k == x:
                    count += 1

    print(count)