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 JAVA (judge verdict: Accepted)

import java.io.*;

class Main {
    public static void main(String[] args) throws IOException {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));

        while(true) {
            String[] tmp = br.readLine().split(" ");
            int n = Integer.parseInt(tmp[0]);
            int x = Integer.parseInt(tmp[1]);
            if (n == 0 && x == 0) {
                break;
            }
            int count = 0;
            for(int i = 3;i <= n;i++){
                for(int j = 2;j < i;j++){
                    for(int k = 1;k < j;k++){
                        if((i + j + k) == x){
                            count++;
                        }
                    }
                }
            }
            System.out.println(count);
        }
    }
 
}