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: Accepted)

#include<stdio.h>
int main(){

	int n,x,i,j,k,count=0;
	
	while(1){
	scanf("%d %d",&n,&x);
	if(n==0 && x==0) break;

	for(i=1; i<=n; i++){
		for(j=1; j<=n; j++){
			for(k=1; k<=n; k++){
				if(i+j+k==x && i<j && j<k)
					count++;
			}}}
	printf("%d\n",count);
	count=0;
	}
	return 0;
}