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)

// 1 から n までの数の中から、重複無しで３つの数を選びそれらの合計が x となる組み合わせの数を求めるプログラムを作成して下さい。
import java.util.Scanner;

class Main{
	public static void main(String[] args){
		Scanner scan = new Scanner(System.in);
		String str = null;
		String[] spl = new String[2];
		int i, j, k;
		int n, x, comp;
		int result = 0;

		while(true){
			result = 0;
			str = scan.nextLine();
			spl = str.split(" ");
			n = Integer.parseInt(spl[0]);
			x = Integer.parseInt(spl[1]);

			if(n==0 && x==0){
				break;
			}
			// 3重ループで重複なしでの足し算組み合わせ特定、カウンタを1増やす
			for(i=1; i<n; i++){
				for(j=(i+1); j<n; j++){
					for(k=(j+1); k <= n; k++){
						comp = x - (i + j);
						if (k == comp){
							result++;
						}
					}
				}
			}
			System.out.println(result);
		}
	}
}