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)

i = 0
m = Array.new(100, 0)
n = Array.new
x = Array.new
while n[i-1] != 0 || x[i-1] != 0
	n[i], x[i] = gets.split.map(&:to_i)
	i += 1
end
for o in 0..i-2
	for j in 1..n[o]-2
		for k in j+1..n[o]-1
			for l in k+1..n[o]
				m[o] += 1 if j + k + l == x[o]
			end
		end
	end
	puts m[o]
end