• ж, ш, ц, ч, щ (Hissing Sounds)
  • л, р, б, в, г, д, м, н, з (Resonant Sounds)
  • х, п, к, т, ф, с (Voiceless)

7-Letters Spelling Rule:

  • г, к, х, ж, ш, щ, ч

Just to confirm the letters so that I can fully understand how to construct the 6 cases.