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 Ruby (judge verdict: Accepted)

while true
	n,x = gets.split.map(&:to_i)
	if n == 0 && x == 0
		break
	end
	a = 1
	b = 1
	c = 0
	cnt = 0
	for a in 1..(n-2) do
		for b in (a+1)..(n-1) do
			c = x - a - b
			if c <= n && c > b && a != b
				cnt += 1
			end
		end
	end
	puts cnt
end