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: Time Limit Exceeded)

#include <stdio.h>

int main(void)
{
 int n,x,ans=0,i,j,k;

 scanf("%d %d",&n,&x);

 while(1){
  if(n==0&&x==0) break;
  for(i=1;i<=n-2;i++){
   for(j=i+1;j<=n-1;j++){
       for(k=j+1;k<=n;k++){
        if(i+j+k==x) ans++;
       }
    }
  }
}

 printf("%d\n",ans);

 return 0;

}