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>
main(){
  int a,b,c,d,e,f,g=0;
  while(1){
    g=0;
    scanf("%d %d",&a,&b);
    if(a==0&&b==0)break;
    for(c=1;c<a+1;c++){
      for(d=1;d<a+1;d++){
	for(e=1;e<a+1;e++){
	  f=c+d+e;
	  if(f==b && c!=d && d!=e && c!=e && c<=d &&d<=e){
	    g=g+1;
	  }
	}
      }
    }
    printf("%d\n",g);
  }
  return 0;
}