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)

ans = []
loop do
    input = gets.split(" ")
    if input[0] == "0" && input[1] == "0"; break; end
    n = input[0].to_i
    x = input[1].to_i
    sum = 0
    1.upto(n) do |a|
        (a+1).upto(n) do |b|
            (b+1).upto(n) do |c|
                if a != b && b != c && a != c && (a + b + c == x)
                    sum += 1
                end
            end
        end
    end
    ans << sum
end
puts ans