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)

while true
	a,b = gets.chomp.split(" ").map &:to_i
	break if a == 0 and b == 0

	c = 0
	a.times { |i|
		next if i >= b
		a.times { |j|
			break if i+j >= b
			next if j <= i
			a.times { |k|
				break if i+j+k > b
				next if k <= j or i+j+k < b
				c += 1
			}
		}
	}

	puts c
end