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: Accepted)

#include <stdio.h>

int main(void)
{
	int n, x, A, B, C, count = 0;
	while (1)
	{
		scanf("%d %d", &n, &x);
		if (n == 0 && x == 0)
			break;
			for (A = 1; A <= n; A++)
			{
				for (B = 1; B <= n; B++)
				{
					for (C = 1; C <= n; C++)
					{
						if (A + B + C == x)
						{
							if (A != B && B != C && C != A)
							{
							count++;
							}
						}
					}
				}
			}
	printf("%d\n", count/6);
	count = 0;
	}
	return 0;
}