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)

module Main where

import Data.Functor

main :: IO ()
main =  do
 { nx@[n,x] <- getInts
 ; if nx == [0,0] then done
   else do print $ sum [ 1 | a <- [1..n], b <- [a+1 .. n], c <- [b+1 .. n], x == a+b+c ]
           main
 }

done :: IO ()
done = return ()

getInts :: IO [Int]
getInts = map read . words <$> getLine