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 = []
while true
  count, value = gets.split(" ").map(&:to_i)
  break if count.zero? && value.zero?
  sum = 0
  memo = []
  (1..count).each do |val1|
    (1..count).each do |val2|
      next if val2 < val1 || val2 == val1
      (1..count).each do |val3|
        next if val3 < val2 || val2 == val3
        sum += 1 if val1 + val2 + val3 == value
      end
    end
  end
  ans << sum
end

puts ans