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)

using System;

class ITP1_7_B{
    static void Main(string[] args){
        int n,x;
        while(true){
            string[] str = Console.ReadLine().Split(' ');
            n = int.Parse(str[0]);
            x = int.Parse(str[1]);
            if(n+x == 0) break;
            int count = 0;
            for(int i=1; i<=n; i++){
                for(int j=1; j<=n; j++){
                    for(int k=1; k<=n; k++){
                        if((i!=j)&&(j!=k)&&(i!=k)){
                             int total = i + j + k;
                            if(total==x){
                                count++;
                            }
                        }
                    }
                }
            }
            Console.WriteLine(count/6);
        }
    }
}