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.util.*;

public class Main {
    private static final Scanner scn = new Scanner(System.in);
    private static final int[][] tbl_;
    private static final int N = 101, X = 298;
    
    static {
        int[][] tbl = new int[N][X];
        for(int i = 3; i < N; i++) {
            double v = 1;
            for(int j = i + 3; j <= (i - 1) * 3; j++) {
                for(int k = i; k < N; k++) {
                    tbl[k][j] += (int)v;
                }
                if(j < i * 2) {
                    v += 0.5;
                } else {
                    v -= 0.5;
                }
            }
        }
        tbl_ = tbl;
    }
    
    public static void main(String[] args) {
        while(scn.hasNextInt()) {
            int n = scn.nextInt(), x = scn.nextInt();
            if(n > 0) {
                System.out.println(0 < x && x < X ? tbl_[n][x] : 0);
            }
        }
    }
}