using System;

public enum AnimalGroup {Mammal, Bird, Fish};
public enum Sex {Male, Female};

public class Animal: IComparable<Animal>{
  private string name;
  private AnimalGroup? group;
  private Sex sex;

  public Animal(string name): 
      this(name, AnimalGroup.Mammal, Sex.Male){
  }

  public Animal(string name, Sex sex): 
      this(name, AnimalGroup.Mammal, sex){
  }

  public Animal(string name, AnimalGroup group, Sex sex){
    this.name = name;
    this.group = group;
    this.sex = sex;
  }

  public string Name{
    get{
      return name;
    }
  }

  public AnimalGroup? Group{
    get{
      return group;
    }
  }

  public Sex Sex{
    get{
      return sex;
    }
  }

  public override string ToString(){
    return "Animal: " + name;
  }

  public int CompareTo(Animal other){
    return this.name.CompareTo(other.name);
  }

  public override bool Equals(Object obj){
    if (obj == null)
       return false;
     else if (this.GetType() != obj.GetType())
       return false;
     else if (ReferenceEquals(this, obj))
       return true;
     else if (this.name == ((Animal)obj).name)
       return true;
     else return false;     
  }

}