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: Wrong Answer)

while True:
    n, x = [int(a) for a in input().split()]
    if n == x == 0:
        break
    cnt = 0
    for i in range(1, n):
        flag = False
        for j in range(i + 1, n):
            if flag:
                break
            for k in range(j + 1, n + 1):
                if (i + j + k) == x:
                    cnt += 1
                    flag = True

    print(cnt)