reordering elements of a list

[greenflame]

Thank you all for your replies. The only thing is I do not understand
how the code is working. The following are more particular questions.

Travis: Iam sorry, but I do not know what list comprehension is.
Roberto: I do not understand the first half of the last line of your
code. Also thank you for also teaching me to use '+' to append one list
to another. This will be very useful for me.
Christoph: I do not undertand the map method.

Thanks again for all the help. :)