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.*;

class Main {
    public static void main(String[] args) {
        BufferedReader kb = new BufferedReader( new InputStreamReader( System.in ) );
        try {

            int n, x;
            int cnt, ave3, ave2;
            String[] tmpArray;  
            while( true ) {
                String str = kb.readLine();
                tmpArray = str.split( " " );
                n = Integer.parseInt( tmpArray[0] );
                x = Integer.parseInt( tmpArray[1] );

                if( 0 == n && 0 == x ) {  break; }

                cnt = 0;
                ave3 = x / 3;
                int i, j, k;
                for( i=1; i<ave3; i++ ) {
                    ave2 = ( x-i ) / 2;
                    for( j=i+1; j<=ave2; j++ ) {
                        k = x - i - j;
                        if( j < k && k <= n ) {
                            cnt++;
                        }
                    }
                }
                System.out.println( cnt );    
            }
        } catch( IOException e ) {
            System.err.println( e );
        }
    }
}