val crewCrewCrew = listOf(
        Sloths("Jerry", false),
        Sloths("Bae", true),
        Sloths("Alex", false),
        Pandas("Tegan"),
        Pandas("Peggy")
    )

val compareByNames = Comparator { a: Mammal, b: Mammal ->
  a.name.first().toInt() - b.name.first().toInt()
}

println(crewCrewCrew.sortedWith(compareByNames))