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 C (judge verdict: Time Limit Exceeded)

#include <stdio.h>

int main()
{
   int n[100], x, i, j, k, c, s;
   c = 0;

   for (i = 0; i++; n==0 && x == 0) {
      scanf("%d %d", &n[i], &x);
   }

   for (i = 1; i++; i <= n - 2) {
      for (j = 2; j++; j <= n - 1) {
         for (k = 3; k++; k <= n) {
            s = i + j + k;
            if (s == x) {
               c++;
            }
         }
      }
   }

   printf("%d", c);

   return 0;
}