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)

ret = []
while True:
   cnt = 0
   n, x = map(int, raw_input().split())
   num_arr = [i for i in range(1, n + 1)]

   if (n, x) == (0, 0):
       break

   for i in range(n, 0, -1):
       for j in range(i -1, 0, -1):
           if 0 < x - i - j < j:
               cnt += 1
   ret += [cnt]
for i in ret:
    print i