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