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)

nx = []
while True:
    nx.append([int(i) for  i in input().split(" ")])
    if nx[-1] == [0, 0]:
        nx.pop()
        break

for c in range(len(nx)):
    count = 0
    for i in range(1, nx[c][0]+1):
        for j in range(i+1, nx[c][0]+1, 1):
            for k in range(j+1, nx[c][0]+1, 1):
                if i + j + k == nx[c][1]:
                    count += 1
    print(count)