Let's consider a short message system encryption as follows. First write the character in
the middle position of the SMS text string, (for the even_length string the middle
position is the first one of the middle two) and left two separated parts, then this
proceeds recursively from left to right. For example, for the word orthography:
The middle character is 'g', we write 'g' down and the word is slipped into two parts
'ortho ' and 'raphy '. Then for the first part 'ortho ' the middle is 't', and left 'or'
and 'ho', then write 'o', 'r' and 'h', 'o'. And then deal with the 'raphy' part for the
Then got gtorhoprahy.
Now the task is you receive an encrypted SMS, do you know what the SMS means?