## Problem E. Endless expression ≡

• problems
 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 3n + 3n + 3n + ... with specified accuracy (of course, that you are in the Kingdom of Infinity, decimal representation of the expression can be infinitely long).

Your answer will be accepted if it has absolute error at most 10 − 5. More specifically, if your answer is a and the jury answer is b, your answer will be accepted if |a − b| ≤ 10 − 5.

### Input format

The first line contains an integer n.

### Output format

Print the value of this infinite expression with specified accuracy.

### Constraints

− 1018 ≤ n ≤ 1018

### Sample tests

No. Standard input Standard output
1
1

1.32471796

2
67738
40.77223943

3
-2184

-13.00000000


0.071s 0.012s 13