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 Haskell (judge verdict: Time Limit Exceeded)

main = interact $ unlines . map (show . itp1_7_b . map read . words) . init . lines

itp1_7_b [n,x] = if x > 297 then 0 else itp1_7_b' 3 1 x
 where
  itp1_7_b' a n' x'
   | a == 1 && x' == n' = 1 
   | n' == n || n' > x' = 0
   | x' <= 0 = 0
   | otherwise = itp1_7_b' (a-1) (n'+1) (x'-n') + itp1_7_b' a (n'+1) x'