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()
{
	int x,n,i,j,k,flag;
	while(scanf("%d%d",&n,&x)==2&&(n!=0))
	{
		flag=0;
		for(i=1;i<=n-2;i++)
		{
			for(j=2;j<=n-1;j++)
			{
				for(k=3;k<=n;k++)
				{
					if(i==j||i==k||j==k)continue;
					if(i+j+k==x&&i<j&&j<k)
					{
						flag++;
					}
						
				}
			}
		}
		printf("%d\n",flag);
	} 
	return 0;
}