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 a,b,c,anc=0;
	for(;;){
		scanf("%d %d",&n,&x);
		if(n>=3&&n<=100&&x>=0&&x<=300){
			if(n==0&&x==0) break;
			if(x>=6&&x<=297){
				if(n>=x){
					for(a=x-3;a>=(x-3)/2;a--){
						b=x-a;
						for(c=b-1;c>(b-1)/2;c--){
							if(b-c!=c) anc++;
						}
					}
				}
				else {
					for(a=n;a>(n-1)/2;a--){
						for(b=a-1;b>(a-1)/2;b--){
							if(a-b!=b) anc++;
						}
					}
				}
				
			}
			printf("%d\n",anc);
		}
	}
	return 0;
}