An animal shelter, which holds only dogs and cats, operators on a strictly "first in, firs tout" basis. People must adopt either the "oldest" (based upon arrival time) of all animals at the shelter or they can select whether they would prefer a dog or a cat (and will receive the oldest animal of that type). They cannot select which specific animal they would like. Create the data structures to maintain this system and provide pseudocode for the operations enqueueDog, enqueueCat, dequeueAny, dequeueDog, and dequeueCat.