H. He's Circles
time limit per test: 10 sec.
memory limit per test: 65536 KB
input: standard
output: standard
He
wrote n letters "X" and "E" in a circle. He thought that there were 2n
possibilities to do it, because each letter may be either "X" or "E".
But Qc noticed that some different sequences of letters can be
transformed one to another with a circular shift (thus representing
actually the same circular string).
For example, strings "XXE"-"XEX"-"EXX" are actually the same.
Qc wants to know how many different circular strings of n letters exist. Help him to find that out.
Input
The input file contains a single integer 1 <= n <= 200000.
Output
Output a single integer --- the number circular strings of length n.
Sample test(s)
Input
Test #1
3
Test #2
4
Output
Test #1
4
Test #2
6
Author: | Anton Golubev, Petrazavodsk SU
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Resource: | Anton Golubev (Hedgehog)'s Contest #2 from Annual Summer Russian Teams Meeting in Petrozavodsk State University
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Date: | August 26, 2005
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Server time: 2005-10-08 15:52:26 | Online Contester Team © 2002 - 2003. All rights reserved. |
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