spoj#COUNTPAS. Counting Pascal

Counting Pascal

Pascal’s triangle is a common figure in combinatorics. It is a triangle formed by rows of integers.
The top row contains a single 1. Each new row has one element more than the previous one
and is formed as follows: the leftmost and rightmost values are 1, while each of the other values
is the sum of the two values above it. Here we depict the first 7 rows of the triangle.

            1            
          1   1          
        1   2   1        
      1   3   3   1      
    1   4   6   4   1    
  1   5   10   10   5   1  
1   6   15   20   15   6   1

Pascal’s triangle is infinite, of course, and contains the value 1 an unbounded number of times.
However, any other value appears a finite number of times in the triangle. In this problem you
are given an integer K ≥ 2. Your task is to calculate the number of values in the triangle that
are different from 1 and less than or equal to K.

Input

The input contains several test cases. Each test case is described in a single line that contains
an integer K (2 ≤ K ≤ 109 ). The last line of the input contains a single −1 and should not be
processed as a test case.

Output

For each test case output a single line with an integer indicating the number of values in Pascal’s
triangle that are different from 1 and less than or equal to K.

Example

Input:
2
6
-1

Output:
1
10