a) Find and find all the files in your home directory (or any subdirectory in it) containing Java source code. Repeat this task with Python source code and music files in mp3 format. b) With the command du you can check how big your files and directories are. How much memory in MB does your home directory occupy? Create a list of the 10 largest directories / files (including size) from your home directory, sorted by size. In the three largest directories, check if you still need all the files or if you can erase some "space eaters". c) sort the plates alphabetically by city, ignoring capital letters in city names.