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){
		Scanner scan = new Scanner(System.in);

		while(true){

			//数字の数と、組み合わせで作る数字の入力
			int howManyNumber = scan.nextInt();
			int createNumber = scan.nextInt();
			//組み合わせたものの和
			int combination = 0;
			//成立した組み合わせの数
			int count = 0;

			//ともに０の時に終了
			if(howManyNumber == 0 && createNumber == 0){
				break;
			}

			for(int num1 = 1 ;num1 <= howManyNumber ;num1++){
				for(int num2 = 2 ;num2 <= howManyNumber ;num2++){
					for(int num3 = 3 ;num3 <= howManyNumber ;num3++){
						//数字の相対的な大きさ決めを重複をはじく
						if(num1 < num2 && num2 < num3){
							combination = num1 + num2 + num3;
							if(createNumber == combination){
								count++;
							}
						}
					}
				}
			}
			System.out.println(count);
		}
		scan.close();
	}
}