In the new center for strange arts (cesa) in new york city, there is a famous weird hall, open 24 hours a day, with a very large painting being perpetually developed by the walk-in artists. because the artists tend to fight with one another as well as accost viewers, only one artist at a time may enter the weird hall, and once an artist is there, no other artists or viewers are allowed in. (they have to wait in front of the weird hall.) if no artist is in, the viewers may come in at any time and in any numbers; they are not queued behind the artists. furthermore, as long as there is at least one viewer is in the weird hall, no artist is allowed in. write the pseudo-code for synchronization of viewers and artists using semaphores.