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)

loop do
  n, x = gets.chomp.split(' ').map(&:to_i)
  break if [n, x] == [0, 0]
 
  cnt = 0
  # n + n + 1 + n + 2 = x
  for i in 1 .. x / 3 - 1
    #i + n + n + 1 = x
    for j in i + 1 .. (x - i - 1) / 2
      k = x - i - j
      if j < k
        cnt += 1
      end
    end
  end
 
  puts cnt
end