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>
#include <string>
using namespace std;

int main()
{
	while (true)
	{
		int count = 0;
		int ax[10000][3] = { 0 };
		int ai = 0;
		int n, x;
		cin >> n >> x;
		if (n == 0 && x == 0) break;
		else
		{
			for (int i = 1; i <= n; i++)
			{
				for (int j = 1; j <= n; j++)
				{
					if (i != j)
					{
						for (int k = 1; k <= n; k++)
						{
							if (i != k && j != k && i + j + k == x)
							{
								//cout << i << " " << j << " " << k << endl;
								int i2 = i;
								int j2 = j;
								int k2 = k;
								if (i2 > j2)
								{
									i2 = j;
									j2 = i;
								}
								if (j2 > k2)
								{
									k2 = j2;
									j2 = k;
								}
								if (i2 > j2)
								{
									int i3 = i2;
									i2 = j2;
									j2 = i3;
								}
								if (j2 > k2)
								{
									int k3 = k2;
									k2 = j2;
									j2 = k3;
								}
								bool is = true;
								for (int c = 0; c < 10000; c++)
								{
									if (ax[c][0] == i2 && ax[c][1] == j2 && ax[c][2] == k2)
									{
										is = false;
									}
								}
								if (is)
								{
									ax[ai][0] = i2;
									ax[ai][1] = j2;
									ax[ai][2] = k2;
									ai++;
									count++;
									//cout << i2 << " " << j2 << " " << k2 << endl;
								}
							}
						}
					}
				}
			}
		}
		cout << count << endl;
	}
}