J. Just One More Bro, I Swear
time limit per test
1 second
memory limit per test
256 megabytes
input
standard input
output
standard output

Eddard is preparing the Game of Coders problemset, but he can't stop adding hard problems to the contest. His secret partner keeps begging him to make it a little easier, but he gets excited whenever he finds an idea for a hard problem, and he can't find any interesting ideas for easy ones. So his partner decided to take matters into their own hands and make this problem.

Given the number of problems in a contest Eddard will prepare, what is the expected number of hard problems?

Input

The input consists of a single integer $$$n$$$ $$$(1 \le n \le 15)$$$ – the number of problems.

Output

Print a single integer, the expected number of hard problems.

Examples
Input
12
Output
12
Input
10
Output
10
Input
15
Output
15
Input
3
Output
3
Note

This is not a trick, just print the input back :3