## Problem E. Endless expression ≡

 Author: N. Grebenyuk Time limit: 1 sec Input file: Standard input Memory limit: 256 Mb Output file: Standard output

### Statement

«To infinity and beyond»

You are now in the Kingdom of Infinity.

In order to escape you need to find the value of the endless expression [3]n + [3]n + [3]n + ... with specified accuracy (of course, that you are in the Kingdom of Infinity, decimal representation of the expression can be infinitely long).

### Input format

The first line contains an integer n.

### Output format

Print the value of this infinite expression with specified accuracy.

1018 ≤ n ≤ 1018

### Sample tests

No. Standard input Standard output
1
1

1.32471796

2
67738
40.77223943

3
-2184

-13.00000000


0.046s 0.009s 15