A. Bashar and SHAWERMA!
time limit per test
1.5 seconds
memory limit per test
256 megabytes
input
standard input
output
standard output

Bashar Loves SHAWERMA sandwiches very much, so he decided to buy some sandwiches.

The price of one sandwich is 2 JDs and Bashar wants to eat $$$x$$$ sandwiches.

how many JDs Bashar needs to buy the $$$x$$$ sandwiches?

Input

The input contains a single integer $$$x$$$ $$$(1 \leq x \leq 30 )$$$ .

Output

Print the number of JDs Bashar needs to buy the $$$x$$$ sandwiches.

Example
Input
17
Output
34