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 i, m, f, r;
	char record;

	while (1) {
		scanf("%d %d %d", &m, &f, &r);
		if ( m + f + r == -3 ) {
			break;
		}
		scanf("\n");
		if ( m == -1 || f == -1 ) {
			record = 'F';
		} else if ( m + f >= 80 ) {
			record = 'A';
		} else if ( m + f >= 65 ) {
			record = 'B';
		} else if ( m + f >= 50 ) {
			record = 'C';
		} else if ( m + f >= 30 ) {
			record = 'D';
			if  ( r >= 50 ) {
				record = 'C';
			}
		} else {
			record = 'F';
		}
		printf("%c\n", record);
	}

    return 0;
}