Mirko received a message from his friend Slavko. Slavko, being a world-class cryptologist, likes to encrypt messages he sends to Mirko. This time, he decided to use One Time Pad encryption. OTP is impenetrable if used correctly, and Slavko knows this. He however, doesn't want Mirko to bang his head on an impossible task, so he sent a few hints along with his message.
Mirko knows that Slavko's original plaintext contained only small
letters of the English alphabet (a
- z
), full stop .
and
space
(ASCII 0
to 9
as his key. After much thought, he realized he can
determine locations of all spaces and full stops in the plaintext. He
now asked you to write a program that will do so automatically.
From his previous dealings with Slavko, Mirko knows how OTP encryption
works. Let's look at a simple example. Suppose you want to encode the
string abc efg
using the key 0120123
.
Start | ASCII Hexadecimal | Encrypted Message |
---|---|---|
abc efg 0120123
|
61 62 63 20 65 66 67 30 31 32 30 31 32 33
|
51 53 51 10 54 54 54
|
First, you transform both the key and plaintext into hexadecimal numbers using ASCII encoding. Then you align them and perform the XOR operation on each pair. The resulting sequence is the encrypted message.
Input Specification
The first line of input contains one integer
The next line contains
Output Specification
The first and only line of output should contain -
, if not, you should output a full stop
.
.
Sample Input 1
7
51 53 51 10 54 54 54
Sample Output 1
---.---
Sample Input 2
7
53 53 51 54 54 51 10
Sample Output 2
------.
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