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.io.BufferedReader;
import java.io.InputStreamReader;

public class Main {

	public static void main(String[] args) throws Exception {
        // TODO ?????????????????????????????????????????????
        
        try (BufferedReader br = new BufferedReader(new InputStreamReader(System.in))) {
            String line;
            int n=0,s=0,sum=0;
            boolean end=false;
            while ((line = br.readLine()) != null) {
            	if(line.equals("0 0"))break;
            	String[] str=line.split(" ");
            	sum=0;
            	n=Integer.parseInt(str[0]);
            	s=Integer.parseInt(str[1]);
            	for(int i=n;i>0;i--){
            		for(int j=i-1;j>0;j--){
            			end=true;
            			for(int k=j-1;k>0;k--){
                    		if(i+j+k==s){
                    			sum++;
                    		}
                    		/*if(i+j+k>=s){
                    			end=false;
                    		}*/
                    	}
            			if(end){
                			end=false;
                		}
                	}
            		if(end){
            			break;
            		}
            	}
            	System.out.println(sum);
            }
        }
    }

}