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;	//Scannerクラス：Java標準入力を取得する

class Main{
	public static void main(String[] args) {
		try(Scanner sc = new Scanner(System.in)){
			for(;;) {
				int n = sc.nextInt();
				int x = sc.nextInt();
				if(n==0&&x==0) break;
				int num = 0;	//出力
				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)
								num++;
						}
					}
				}
				System.out.println(num);
			}
		}
	}
}