Description

Xiaoming has $n$ apples at home. Before going to bed each day, she can eat $1$ to $2$ apples. Xiaoming also has an older sister named May, who eats $1$ apple each day after Xiaoming goes to sleep (to be considerate of her younger sister). If there are no apples left, May won't eat any. How many different ways are there to eat the apples?

Input Format

A single integer $n$ ($0 \le n \le 10$).

Output Format

A single integer representing the total number of possible ways to eat the apples.

Sample

5

4