3. Animal Type

string animal = Console.ReadLine();

//1.	dog -> mammal
//2.	crocodile, tortoise, snake -> reptile
//3.	others -> unknown

if (animal == "dog")
{
    Console.WriteLine("mammal");
}
else if (animal == "crocodile" || animal == "tortoise" || animal == "snake")
{
    Console.WriteLine("reptile");
}
else
{
    Console.WriteLine("unknown");
}