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.*;
import java.io.*;
 
class Main{
    public static void main(String args[])throws IOException{
       BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
       String s;
       while((s=br.readLine())!=null){
           String[] str = s.split(" ");
           int n = Integer.parseInt(str[0]);
           int x = Integer.parseInt(str[1]);
           if(n==0 && x==0) break;
           int count=0;
           for(int i=1; i<n; ++i){
               for(int j=i; j<n; ++j){
                   if(i==j) continue;
                   int num = x - (i+j);
                   if(num<1) break;
                   if(num<j) break;
                   if(i != num && j != num && num <= n) count++;
                   num = 0;
               }
           }     
       System.out.println(count);
       }
    }
}