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)

import sys
input = lambda: sys.stdin.readline().rstrip() 

def resolve():
    while True:
        n, x = map(int, input().split())
        if n==0 and x==0:
            break
        else:
            ans = 0
            for i in range(1, n-1):
                for j in range(i+1, n):
                    for k in range(j+1, n+1):
                        if i+j+k==x:
                            ans += 1
            print(ans)

if __name__ == '__main__':
    resolve()