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