+--> Fizika
  |   |--> 2.c
  |   |--> 2.e
  |   |--> 4.a
  |   |--> 4.b
  |   |--> 4.c
  |   |--> 4.d
  |   `--> 4.e
  | | +--> 1A
  | | +--> 1C
  | | +--> 2A
  | | +--> 3A
  | | +--> 4A
  +--> TZK