a$)$ Examine the following pseudo code in which p and q$,$ defined as shown below. A$,$ B$,$ C$,$ D$,$ and E atomic $($indivisible$)$ statements. Assume that the main program execute these two processes concurrently. $(10$ pts$)$

void p$()\{$

C$=$B$-1//1$

B$=2*$C $//2$

$\}$

void q$()\{$

D$=2*$B $//3$

B$=$D$-1//4$

$\}$

Initial value of B is $2.$

Void main$()$

$\{$

Parbegin p$(),$ q$()//$Call method p$()$ and method q$()$ simultaneously

$\}$

Considering all possible execution paths of this program explain how many different paths and how many different values of B can be obtained.