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){
		//データの読み込みの準備
		Scanner sc = new Scanner(System.in);
		
		while(true){
			//結果格納用変数
			int counter = 0;
			
			//データの読み込み
			int n = sc.nextInt();
			int x = sc.nextInt();	
			
			//終了条件の判定
			if(n == 0 && x == 0){
				break;
			}
			
			for(int i = n; i >= 3; i--){
				for(int j = i - 1; j >= 2; j--){
					//iとjを確定とした時に、残りの値を決定する
					int remainder = x - i - j;
					
					//remainderが初期条件を満たしているかで、条件分岐
					if (remainder <= 0){
						continue;
					}else if (remainder >= j){
						break;
					}else{
						counter++;
					}
				}
			}
			
			System.out.println(counter);
		}
	}
}