Олимпиадный тренинг

Задача 21779. MLGpro


Задача

Темы:
abcPR0smoke-w33d really wants to become an MLG pro and get into the FaZe clan. To do this, he practices shooting with a sniper rifle every day. As a reward, for every noscope he gets 2 packs of doritos, and for every quickscope he gets one. How many options to make shots did abcPR0smoke-w33d have if he ended up with n - 1 bursts.
Input:
The input is the number n (1 <= n <= 50).
Output:
Print one number - the number of options to make shots. 
 
Input example:
3
Sample output:
2

Author: Bukov Anton