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 <iostream>
using namespace std;
int main()
{
	int n, x;
	int c = 0;
	while (true)
	{
		cin >> n >> x;
		if (n == 0 && x == 0)
		{
			break;
		}

		int count = 0;
		for (int x1 = 1; x1 <= n; x1++)
		{
			for (int x2 = 1; x2 <= n; x2++)
			{
				for(int x3 = 1; x3 <= n; x3++)
				{
					if (x1 == x2 || x1 == x3 || x2 == x3)
					{
						continue;
					}

					int result = x1 + x2 + x3;
					if (result == x)
					{

						count++;

					}
				}
			}
		}
		cout << count / 6 << endl;
	}
	return 0;
}