You are given two Finite Automata $($FA$),$ FA$1$ and FA$2,$ as shown below.

On a piece of paper, use the algorithm of Kleene's theorem to construct FA$3,$ the union language FA$1+$ FA$2.$ Then answer the following question:

How many final states does FA$3$ have?

$($your answer must be a integer number, such as $5!)$

$6$

$3$

$1$

$0$