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 <bits/stdc++.h>

using namespace std;

int main() {
    while (true) {
        int ans = 0;
        int n, x;
        cin >> n >> x;
        if (n == 0 && x == 0) {
            break;
        }
        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) {
                        continue;
                    }
                    if (i + j + k == x) {
                        ans++;
                    }
                }
            }
        }
        cout << ans << endl;
    }
    return 0;
}