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
import Control.Applicative

ways n x = let allComb = [(a,b,c) | a <- [1..n], b <- [1..n], c <- [1..n], a < b && b < c] in
    length $ filter (\(l,m,n)->l+m+n == x) allComb

processInputLine [n,x] =
    if n == 0 && x == 0 then return () else print $ ways n x

main = do
    mapM_ processInputLine =<< map (map (read :: String->Int) . words) <$> lines <$> getContents