static void Main(string[] args)
{
Person p1 = new Person("Sam", "Newton", "16/06/1996", 183);
Person p2 = new Person("Jordan", "Cadzow", "29/05/2001", 180);
Person p3 = new Person("Killmaim", "Deathstab", "1/01/2020", 143);
Console.WriteLine(p1.GetFullName());
Console.WriteLine(p2.GetFullName());
Console.WriteLine(p3.GetFullName());
Console.WriteLine(p1.GetHeightDifference(p2));
Console.WriteLine(p1.GetHeightDifference(p3));
Console.WriteLine(p2.GetHeightDifference(p3));
}