Person sam = new Person("Sam", 25);
sam.Print();

class Person
{
    public string name;
    public int age;
    public Person() : this("Unknown") { }
    public Person(string name) : this(name, 18) { }
    public Person(string name, int age)
    {
        this.name = name;
        this.age = age;
    }
    public void Print() => Console.WriteLine($"Name: {name} Age: {age}");
}