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)

result = []
while True:
    count, target = map(int, input().split())
    if count == target == 0: break
    lis = [i for i in range(1, count+1)]

    result = 0
    for n1 in lis:
        for n2 in lis[n1:]:
            for n3 in lis[n2:]:
                if n1+n2+n3 == target:
                    result += 1
    
    print(result)