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(){
  int n,x,i,j,k,a;
  int d=0;
  for(a=0;a<10000;a++){
    d=0;
  scanf("%d %d",&n,&x);
  if(n == 0 && x == 0)
    break;
  for(i=1;i<=n-2;i++){
    for(j=1;j<=n-1;j++){
      for(k=1;k<=n;k++){
    if(i == j || j == k || i == k){
    }else if(i > j || j > k || i > k){
    }else if(i+j+k == x){
      d++;
    }
      }
    }
  }
  printf("%d\n",d);
  }
  return 0;
}