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)

solve :: Int -> Int -> Int
solve n x = length [[a,b,c] | a <- [1..n], b <- [1..n], c <- [1..n], a + b + c == x, a /= b, b /= c, a /= c] `div` 6

main = do
	[n,x] <- fmap (map read . words) getLine
	if [n,x] == [0,0]
		then return ()
		else do
			putStrLn $ show $ solve n x
			main