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(void) {

	int a,b;
	int i,j,k,l=0,m[1000]={0};

	while(1){
		scanf("%d%d",&a,&b);
		
		if(a==0&&b==0){
			break;
		}
		
		for(i=1;i<a+1;i++){
			for(j=2;j<a+1;j++){
				for(k=3;k<a+1;k++){
					if(b==(i+j+k)&&i<j&&j<k){
						m[l]=m[l]+1;
					}
				}
			}
		}
		
		l++;
	}
	
	for(i=0;i<l;i++){
		printf("%d\n",m[i]);
	}
	
	return 0;
}