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;
  int b,i,j,k,a;
 
  while(1) {
    scanf("%d %d",&n,&x);   
    b = 0;
    if( n == 0 && x == 0){
      break;
    }
    for(k = 1; k <= n ; k++) {
 
 
      for(j = 1; j <= n ; j++) {
 
    for(i = 1; i <= n; i++) {
       
      if(i == j || j == k || i ==k) {
         
      }else{
        a = i + j + k;
        if(a == x) {
          
          b += 1;
  
        }
      }
       
    }//i
     
      }//j
 
    }//k
    printf("%d\n",b/6);
  }
 
 
  return 0;
}