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 x, y;
    int i , j, k, sum;
    int count =  1 ;
    
	
	while ( 1 ) {   
	 scanf("%d %d", &x, &y);
          if (x + y == 0) {
	    break ;
	    }
             for ( i = 1 ; i <= x; x++ ) {
	 	for ( j = i ; j <= x ; j++ ) {
			for ( k= j ; j <= x ; k++) {
				sum = i + j + k ; 
				if ( sum == y ) {
					count++ ;
				}
			}
		 }
	       }
	printf("%d\n", count) ;
	}

return 0;
}