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 set;
	int tag;
	int mid;
	int i, j;
	int count = 0;
	
	while(1){
		scanf("%d %d", &set, &tag);
		if(set == 0 && tag == 0){
			break;
		}
		for(i = 1;i < set;i++){
			for(j = i;j <= set;j--){
				mid = tag - (i + j);
				if(mid > i && mid < j){
					count++;
				}
			}
		}
		printf("%d\n", count);
	}
	return 0;
}