Suppose that two threads A and B have access to the shared variable $$account$,$ which

has the initial value of $100$; Now, thread A is going to make a deposit and perform: $$account

$=$ account $+200,$ while thread B is going to do a withdraw: $$account $=$ account $50.$

$1)$ What are the possible values of the variable after running the two threads without having

a synchronization mechanism for the critical section?

$2)$ Use semaphore to address the critical section problem