+--> Fizika
  | | ---> PAU
  | | | +--> 2E
  | | | ---> 3E
  | | | | `--> Test
  | | | +--> 4E
  | | +--> SJZ
  | | |--> 1 a
  | | |--> 1b
  | | |--> 1 d
  | | |--> 2 a
  | | |--> 3 a
  | | |--> 3 c
  | | |--> 4 a
  | | `--> 4 C
  +--> TZK