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.Applicative
import Control.Monad
import Data.Array
import Data.Array.ST
import Data.List
import qualified Data.Map as M
import qualified Data.Set as S
import Text.Printf

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

main :: IO ()
main = do
  [n,x] <- readInts
  when ((n,x) /= (0,0)) $ do
    print $ solve n x
    main

solve :: Int -> Int -> Int
solve n x = length [ (a,b,c) 
                   | a <- [1..n], b <- [a+1..n], c <- [b+1..n]
                   , a + b + c == x
                   ]