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)

// ITP1_7_B How many ways?
import java.io.*;

public class Main {

   public static void main(String[] args) {
      try {
         BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
         
         while (true) {
            String strAry[] = br.readLine().split(" ");
            int n = Integer.parseInt(strAry[0]);
            int x = Integer.parseInt(strAry[1]);

            if ((n == 0 && x == 0) || (n < 3 || n > 100))
               break;

            System.out.println(combination(n, x));
         }
      }

      catch (Exception e) {
         System.err.println(e);
      }
   }

   private static int combination(int n, int x) {
      int count = 0;
      int a, b, c;
      for (int i = 1; i <= n; i++) {
         for (int j = 1; j <= n; j++) {
            if (i == j)
               break;
            for (int k = 1; k <= n; k++) {
               if (i == k || j == k)
                  break;
               if (i + j + k == x)
                  count++;
            }
         }
      }

      return count;
   }
}