who is the fool

 This is crime story :
5 friends lived in a room
namely 1.mad 2.brain 3.fool
4.somebody 5.nobody.
one day, somebody killed nobody
that time brain was in bath room,
mad called police.

mad: is it police  station?
police: yes, what is matter?
mad: somebody killd nobody
police: are you mad?
mad: yes i am mad.
police: don't u have brain.
mad : brain is in bathroom.
police: u fool
mad : no, fool is reading...