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, x, i, j, k;
   int l = 0;
   
   scanf("%d %d", &n, &x);

   while(1) {

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

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

   printf("%d\n", l);
   return 0;
}