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)

/*
 ============================================================================
 Name        : 7b.c
 Author      : 
 Version     :
 Copyright   : Your copyright notice
 Description : Hello World in C, Ansi-style
 ============================================================================
 */

#include <stdio.h>
int main(){
int n,x,suji,suji2,suji3,goukei,count;
count=0;
		for(;;){
	scanf("%d %d",&n,&x);
	if(n==0 && x==0)break;
	for(suji=1;suji<n-2;suji++){
		for(suji2=2;suji2<n-1;suji++){
			for(suji3=3;suji3<n;suji3++){
				goukei=suji+suji2+suji3;{
					if(goukei==x){
						count++;

					}
				}
			}
		}
	}
	printf("%d",count);
		}
		return 0;
}