Which one is not the part of brain?

Pons is a part of Brainstem, it connects different parts of the brain. It also regulates different functions like Sleeping and Breathing.
Medulla Oblongata is also part of Brainstem, it control different vitals i.e. Heart Beat Rate and Reparation Rate.
Hindbrain is main part of brain which consist of Pons, Medulla Oblongata and Cerebellum.
The brain is divided into three parts which are The Forebrain, The Midbrain and the Hindbrain.