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 = '';
var readable = process.stdin;
readable.resume();
readable.setEncoding( 'utf-8' );
readable.on( 'data', function( chunk ) {
  input += chunk;
});

readable.on( 'end', function() {
  var data = input.split( '\n' );
  var output = [];
  for( var index=0; index<data.length; index++ ) {
    var nums = data[index].split( ' ' ).map( Number );
    var n = nums[0];
    var x = nums[1];
    if( 0 == n && 0 == x ) { break; }

    var cnt = 0;
    var ave = x/3;
    for( var i=1; i<ave; i++ ) {
      var t = (x-i)/2;
      for( var j=i+1; j<t; j++ ) {
        var k = x-i-j;
        if( j < k && k <= n ) { cnt++; }
      }
    }
    output.push( cnt );
  }
  console.log( output.join( '\n' ) );
});