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 a=0,i,j,k,x,y;
   while(x==0 && y==0){scanf("%d %d",&x,&y);}
      for(i=1;i<x;i++){
         for(j=i;j<x;j++){
            for(k=j;k<x;k++){
   if(i+j+k==y)
      a=a+1;
}}}
printf("%d",a);
return 0;}