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: Time Limit Exceeded)

'''
ITP-1_7-B
 ????????????????????°
1 ?????? n ?????§?????°?????????????????????????????§???????????°?????????????????????????¨???? x ??¨??????????????????????????°???
?±???????????????°?????????????????????????????????
????????°???1 ?????? 5 ?????§?????°???????????????????????§????????????????¨???? 9 ??¨???????????????????????????
1 + 3 + 5 = 9
2 + 3 + 4 = 9
??????????????????????????????
???Input
?????°??????????????????????????\?????¨??????????????????????????????????????????????????§??????
????????§??????????????? n???x ??? 1 ???????????????????????????
n???x ?????¨?????? 0 ?????¨?????\?????????????????¨????????????
n ??? 3 ??\??? 100?????\?????¨????????????
???Output
????????????????????????????????????????????????????????°????????????????????????????????????
'''
n, x = map(int, input().split())

while True:

    # EndCheck
    if n == x == 0:
        break

    ansCnt = 0
    for cnt1 in range(1,n+1):
        for cnt2 in range(cnt1+1,n+1):
            for cnt3 in range(cnt2+1,n+1):
                if cnt1 + cnt2 + cnt3 == x:
                    ansCnt += 1
                    break
    print(ansCnt)