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: Accepted)

import Control.Monad

toIntList list = map (\x -> read x :: Int) . words $ list

getTrio n x = [(a, b, c) | a <- [1..n], b <- [a..n], c <- [b..n], a < b, b < c, a + b + c == x]

main = do
  a <- return . filter (/= [0, 0]) . map toIntList . lines =<< getContents
  mapM_ (print . length) $ map (\[n, x] -> getTrio n x) a