Correct

脑残

/ nǎo cán / 
Strokes

Definition

moronic/brainless/bonehead/retard

Example

As a Noun

mentally-retarded person; brain-damaged person

1
Nǐ
你
nǎocán
脑残
le
了
  
?

Don't be such a fool!

As a Noun

fool; idiot

2
Nǐ
你
nǎocán
脑残
le
了
  
?

you idiot!