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 JAVA (judge verdict: Accepted)

import java.util.Scanner;

public class Main {

	public static void main(String[] args) {

		int n = 0;
		int x = 0;
		int cnt;

		Scanner sc= new Scanner( System.in );

		while ( true ) {
			cnt = 0;
			
			n = sc.nextInt();
			x = sc.nextInt();

			if ( n == 0 && x == 0 ) {
				break;
			}

			for ( int i = 1 ; i < ( n - 1 ) ; i++ ) {
				for  ( int j = ( i + 1 ) ; j < n ; j++ ) {
					for ( int k = ( j + 1 ) ; k < ( n + 1 ) ; k++ ) {
						if ( ( i + j + k ) == x ) {
							cnt++;
						}
					}
				}

			}
			System.out.println( cnt );
		}
		sc.close();
	}
}