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,a = 0,i,j,k;
  while(1){
    scanf("%d %d",&n,&x);
    if(n == 0 && x == 0){
      break;
    }
    for(i = 1; i <= n; i++){
      for(j = 2; j <= n; j++){
        for(k = 3; k <= n; k++){
          if(i != j && j != k && k != i && i + j + k == x && i <  j && j < k){
            a += 1;
          }
        }
      }
    }
    printf("%d\n",a);
    a = 0;
  }
  return 0;
}