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 Slavkos original plaintext contained only small
letters of the English alphabet (a
 z
), full stop .
and
space
( ). Also, he knows that Slavko used only digits
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 0120123
as key.
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 number of characters in the encrypted message.
The next line contains integers, written in hexadecimal, larger than or equal to and smaller than or equal to , the encrypted message.
Output Specification
The first and only line of output should contain characters, each
representing one character in the plaintext. If the th
character of plaintext is a letter, the th character of
output should be a dash 
, 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
.
Comments