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.*;
public class Main {
    static Scanner kbd = new Scanner(System.in);
    public static void main(String[] args) {
 
    while(kbd.hasNext()){
        int n = kbd.nextInt();
        int x = kbd.nextInt();
        int z=0;
        if(!(n==0 && x==0)){
        for(int a=1; a<=n-2; a++){
            for(int b=2; b<=n-1; b++){
            for(int c=3; c<=n; c++){
                //System.out.println(a+" "+b+" "+c);
                if(m(a,b,c,x)) z++;
            }
            }
        }
        System.out.println(z);
        }
    }
    }
    static boolean m(int a, int b, int c, int x){
    boolean p = a+b+c==x;
    boolean q = a<b && b<c;
    return p&&q;
    }
}