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,j,k;
  int comb;

  while(1){
    comb=0;
    scanf("%d %d",&n,&x);
    if(n==0 && x==0){
      break;
    }

    for(i=1;i<=n;i++){
      for(j=1;j<=n;j++){
	for(k=1;k<=n;k++){
	  if(i==j || i==k || j==k){
	    ;
	  }else if(i+j+k==x){
	      comb++;
	  }
	}
      }
    }
    printf("%d\n",comb/6);
  }

  return 0;
}