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: Wrong Answer)

def comb_num(n, x)
	result = 0
	for i in 1..n
		for j in i..n
			for k in j..n
				if (i + j + k == x) && ([i, j, k].uniq == [i, j, k])
					puts [i, j, k]
					result+=1
				end
			end
		end
	end
	return result
end

inputs = gets.strip().split(" ").map{|i| i.to_i}
n, x = inputs[0], inputs[1]

until n == 0 && x == 0
	puts comb_num(n, x)
	inputs = gets.strip().split(" ").map{|i| i.to_i}
	n, x = inputs[0], inputs[1]
end