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)

main = do
    str <- getLine
    let (n:x:_) = map read $ words str
    if ((n,x) == (0,0)) then
        return ()
    else do
        print $ length [(a,b,c) | a <- [1..(n-2)], b <- [(a+1)..(n-1)], c <- [(b+1)..n], a+b+c==x]
        main