class Class1 : Example
    {
    public int a;
    protected double b;
    public double property1
    {
    set { b = value; }
    }
    public int c{ get; }
    public int method1(int x) { return x * x * x; }
    }
    class Class2 : Example
    {
    public int a;
    public double property1 { get; set; }
    public int method1(int x) { return x * x; }
    }
    class Class3 : Example
    {
    public int a;
    public double property1 { get; set; }
    }
interface IHw2
{
// ……..…?.
}

interface Example
    {
         double property1 {set; }
    }