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 m, f, r;
    int score;
    char grade;
 
    while (1) {
        scanf("%d %d %d", &m, &f, &r);
 
        score = m + f;
 
        if (m == -1 && f == -1 && r == -1) break;
 
        if (m == -1 || f == -1 || score < 30) {
            grade = 'F';
        } else if (score >= 80) {
            grade = 'A';
        } else if (score >= 65 && m + f < 80) {
            grade = 'B';
        } else if (score >= 50 && m + f < 65) {
            grade = 'C';
        } else if (score >= 30 && m + f < 50) {
            if (r >= 50) {
               grade = 'C';
            } else {
               grade = 'D';
            }
        }
 
        printf("%c\n", grade);
 
    }
    return 0;
}