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)

MODE = "stdio"
require 'matrix'
line = Array.new

if(defined? MODE)
  line = STDIN.read.split("\n")
else
  tmp = "\
  5 9
  5 6
  10 44
  0 0
  ".split("\n")
  tmp.each{|s|
    line << s.strip
  }
end

n,x=[0,0]
i=0
while true
  n,x = line[i].split(" ").map(&:to_i)
  break if n==0 && x==0
  i += 1
  c =  [*1..n].combination(3)
  puts c.select{|a| a.inject(&:+)==x}.size
end