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.*;

/**
 * @author kawakami
 *
 */
class Main {

	/**
	 * @param args
	 */
	public static void main(String[] args) {
		// TODO Auto-generated method stub
		
		Scanner as = new Scanner(System.in);
		int n,x,i,j,k,t;
		int s = 0;
		String str;
		
		while(true){
			
			n = as.nextInt();
			x = as.nextInt();
			s=0;
			
			if(n == 0 && x == 0){
				break;
			}
			
			for(i=1;i<=n;i++){
				for(j=1;j<=n;j++){
					for(k=1;k<=n;k++){
						
						if(i != j && j != k && i != k){
								
							if((i+j+k) == x){
								
								s++;
								
							}
								
						}
							
					}	
				}	
			}
			
			str=String.valueOf(s/6);
			System.out.println(str);
			
		}
		
		

	}

}