HackerLand Enterprise is adopting a new viral advertising strategy. When they launch a new product, they advertise it to exactly $5$ people on social media.

On the first day, half of those $5$ people (i.e., $floor(\frac{5}{2})=2$) like the advertisement and each shares it with $3$ of their friends. At the beginning of the second day, $floor(\frac{5}{2})\times3=2\times3=6$ people receive the advertisement.

Each day, $floor(\frac{recipients}{2})$ of the recipients like the advertisement and will share it with $3$ friends on the following day. Assuming nobody receives the advertisement twice, determine how many people have liked the ad by the end of a given day, beginning with launch day as day $\mbox{1}$.

Example

$n=5$.

Day Shared Liked Cumulative
1 5 2 2
2 6 3 5
3 9 4 9
4 12 6 15
5 18 9 24

The progression is shown above. The cumulative number of likes on the $5^{th}$ day is $24$.

Function Description

Complete the viralAdvertising function in the editor below.

viralAdvertising has the following parameter(s):

int n: the day number to report

Returns

int: the cumulative likes at that day

Input Format

A single integer, $n$, the day number.

Constraints

$1\leq n\leq50$

Sample Input
3

Sample Output
9

Explanation

This example is depicted in the following diagram:

$2$ people liked the advertisement on the first day, $3$ people liked the advertisement on the second day and $4$ people liked the advertisement on the third day, so the answer is $2+3+4=9$.

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