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 count;
 
  scanf("%d",&n);
  scanf("%d",&x);
  while (!((n==0) && (x==0))){
    count=0;
    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))){
            if (i+j+k==x){
              count++;
 
            }
          }
        }
      }
    }
    printf("%d\n",count/6);
    scanf("%d",&n);
    scanf("%d",&x);
  }
 
  return 0;
}