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(void){
	int n,x;
	int i,j,k;
	int count = 0;
	int sum = 0;
	scanf("%d %d",&n,&x);
	while(1){
		if(n <= 2 || x <= 5){
			break;
		}
		for(i = 1;i < n - 1;i++){
			sum += i;
			for(j = i + 1;j < n;j++){
				sum += j;
				for(k = j + 1;k <= n;k++){
					sum += k;
					if(sum == x){
						count++;
						break;
					}
				}
			}
		}
	}
	printf("%d\n",count);
	return 0;
}