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)

int a(int x,int y){
	int i,j,k,count=0;
	
	for(i=1;i<=x;i++){
		for(j=1;j<=x;j++){
			for(k=1;k<=x;k++){
				if(i<j && j<k && y==i+j+k) count++;
			}
		}
	}
	return count;
}

int main(){
	int x,y;
	while(1){
		scanf("%d %d",&x,&y);
		if(x==0 && y==0) break;
		printf("%d\n",a(x,y));
	}
	return 0;
}