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 JavaScript (judge verdict: Accepted)

var input = require('fs').readFileSync('/dev/stdin', 'utf8');
var Arr=(input.trim()).split("\n");
for(var I=0;I<Arr.length;I++){
   var nx=Arr[I].split(" ").map(Number);
   var n=nx[0];
   var x=nx[1];
   if(n==0 && x==0)break;
   var cnt=0;
   for(var i=1;i<=n;i++){
      for(var j=i+1;j<=n;j++){
         if(i+j>=x)break;
         var k=x-(i+j);
         if(k>j && k<=n)cnt++;
      }
   }
   console.log(cnt);
}