Part B $[12$ marks$]$: Sometimes it is necessary to synchronize two or more processes in a group so that every process must finish its first phase of computation before any other process is allowed to start its second phase. This is called barrier synchronization; For example, for two processes Pl and P $2,$ we can write:

Semaphores: sl $=0,$ s$2=0$;

In this question, you are required to synchronize five processes P$1,$ P$2,$ P$3,$ P$4,$ and P$5.$ The new rules are: $1)$ Process P$1$ must finish both phase I and phase II before any of the other processes can access any of their phases, $2)$ Process P$5$ must finish phase I next, followed by process P$2,$ which must finish Phase I before both P$3$ and P$4$ can start their phase I$\text{'}$s$,3)$ all phase I$\text{'}$s must finish before any phase II starts, and $4)$ all phase II's must proceed in the order $"3254"($that is P$3$ must finish Phase II before P$2,$ and P$2$ must finish Phase II before P$5,$ and finally P$5$ must finish Phase II before P$4).$ You are allowed to use any number of semaphores; however, semaphores cannot be initialized with negative values. Initializing or setting any semaphore to a negative value will result in a total discard of the solution. Fill in the missing synchronization code below: