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(){
    int n, x;
    int a, b, c, ans;
    while(1){
        scanf("%d%d", &n, &x);
        ans = 0;
        for(a = 1;a <= n; a++){
            for(b = 1;b <= n; b++){
                for(c = 1;c <= n; c++){
                    if(a == b || b == c || c == a){
                        continue;
                    }
                    if(x == (a + b + c)){
                        ans++;
                    }
                }
            }    
        }
        
        printf("%d\n",ans);
    }
    return 0;
}