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 Data.Functor( (<$>))

main = do
    ls <- takeWhile ("0 0"/=) . lines <$> getContents
    let
	nxs = (read <$>) <$> words <$> ls
	
	pick [n,x] = [ (a,b,c)	| a<-[1..n-2] 
				, b<-[a+1..n-1] 
				, c<-[b+1..n]
				, a+b+c==x	]

    (print . length . pick) `mapM_` nxs