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(){
  int data[10000][2];
  int i=0,j=0,k=0,l=0;
  int x,n;
  int count=0;
  int counts=0;

  while(1){
    scanf("%d %d",&n,&x);
    if(n==0 && x==0) break;
    data[i][0]=n;
    data[i][1]=x;
    i++;
    count +=1;
  }

  for(l=0;l<count;l++){
  
    for(i=1;i<=data[l][0];i++){
      for(j=1;i<=data[l][0];j++){
	for(k=1;k<=data[l][0];k++){
	  if(i+j+k==data[l][1] && i!=j && j!=k && k!=i) counts+=1;
	}
      }
    }
    printf("%d\n",counts/6);
  }
  return 0;
}