K. Cutting Strings
time limit per test
2 seconds
memory limit per test
512 megabytes
input
standard input
output
standard output

Alice, Beto, and Carlos are playing with twine. Alice starts by pulling taut the string of twine, then she folds it and holds the string at the fold. Beto holds the loose ends on the other side. They then repeat the following procedure. Carlos cuts the string with scissors, thus separating Alice and Beto. Alice, without letting go of the strings she was holding, grabs the loose ends of the strings held by Beto and he does the same to the loose ends of the strings held by Alice.

How many separate strings will they have after the procedure is repeated K times?

Input

The input has a single integer, K.

  • 0 ≤ K ≤ 30
Output

The output has a single integer, the amount of separate strings at the end of the process.

Examples
Input
0
Output
1
Input
1
Output
3