He's Circles#7125

He's Circles

2.5 seconds
64 megabytes
Very easy

Vasya wrote letters "X" and "E" in a circle. He thought that there were 2^n possibilities to do it, because each letter may be either "X" or "E". However, Petya noticed that some different sequences of letters can be transformed into each other by a circular shift (thus representing the same circular string).

For example, the strings "XXE", "XEX", and "EXX" are actually the same.

Petya wants to know how many different circular strings of letters exist. Help him find that out.

Input

The input consists of a single integer (1 \leq n \leq 200000).

Output

Output a single integer: the number of distinct circular strings of length .

Examples

Example 1

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