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.IOException;
import java.io.InputStreamReader;
 
public class Main {

  public static void main(String[] args) throws IOException {
    try ( BufferedReader br = new BufferedReader(new InputStreamReader(System.in)) ) {

      int count = 0;
      int n,x;
      String[] lines;

      while(true){

        lines = br.readLine().split(" ");
        n = Integer.parseInt( lines[0] );
        x = Integer.parseInt( lines[1] );
        if( n == 0 && x == 0) break;

        for( int i = 1; i < n-1; i++ ){
          for( int j = i+1; j < n; j++ ) {
            for( int k = j+1; k <= n; k++ ){
              if ( (i + j + k)  > x ) break;
              if ( (i + j + k) == x ){
                count++;
                // System.out.println( i + " " + j + " " + k);
              }
            }
          }
        }
        System.out.println(count);
        count = 0;
      }
    }
  }
}