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,i,ii,iii,A;
    while(1)
    {
        A=0;
        scanf("%d%d",&n,&x);
        if(n==0&&x==0)
        {
            break;
        }
        for(i=1;i<=n;i++)
        {
            for(ii=1;ii<=n;ii++)
            {
                if(i!=ii)
                {
                    for(iii=1;iii<=n;iii++)
                    {
                        if(i!=iii&&ii!=iii)
                        {
                            if(i+ii+iii==x)
                            {
                                A++;
                            }
                        }
                    }
                }
            }
        }
        printf("%d\n",A/6);
    }
    return 0;
}