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)

def solve():
    n,x = map(int,input().split())
    if n==0 and x==0:
        return False
    ans = 0
    s = set()
    for i in range(1,n+1):
        for j in range(i+1,n+1):
            it = x-i-j
            v = [it,i,j]
            v = sorted(v)
            val = v[0]*1000000+v[1]*1000+v[2]
            if 0<it<=n and it!=i and it!=j and (not val in s):
                s.add(val)
                ans+=1
    print(ans)
    return True
if __name__ == "__main__":
    while(solve()):
        pass