Create a function that returns the selected filename from a path. Include the extension in your answer.
get_filename("C:/Projects/pil_tests/ascii/innokodakademija.txt") ➞ "innokodakademija.txt"
get_filename("C:/Users/johnsmith/Music/Beethoven_5.mp3") ➞ "Beethoven_5.mp3"
get_filename("ffprobe.exe") ➞ "ffprobe.exe"