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)

count = 0
ans = []
xmax = []
num = []

loop do

 prexmax, prenum = gets.split.map &:to_i

 if !( prexmax == 0 && prenum == 0 )
  xmax << prexmax
  num << prenum
  count += 1

 else
  break
 end

end

for c in 0..count-1

 preans = 0

 imax = [num[c]/3-1, xmax[c]].min
 for i in 1..imax

  jmax = [((num[c]-i)/2.to_f).ceil-1, xmax[c]].min
  for j in i+1..jmax

   if num[c]-i-j <= xmax[c] then preans += 1 end

  end
 end

 ans << preans

end

puts ans