Little Piggy decided to categorize his archive containing a lot of different format files. There are pictures, videos, audio, documents, e-tables, documents templates, Web-pages with different file extensions, text of programs in different programming languages and even unknown content files with .hrj extension. Altogether there are 1001111 files. At first Little Piggy decided to move all the pictures into one folder. Thus he selected 5 filtering masks for file names. Most files will be filtered when using the following mask …
Let’s presume that the number of files of every format is relatively similar.