Best way to do this OOP-wise???

namespace namespace1
{
    internal class Program
    {
        
        static void Main(string[] args)
        {
            BaseClass baseClass = new BaseClass();
            DerivedClass1 = new DerivedClass1();//Here I initialize fields in BaseClass
            DerivedClass2 = new DerivedClass2();//Here I want the data initialized in BaseClass on the previous line
        }
    }
}

internal class BaseClass
{
    private protected int someData;
    private protected string someMoreDataStr;
}

internal class DerivedClass1 : BaseClass
{
    \\THIS CLASS INITIALIZES DATA TO THE FIELDS IN BASECLASS
    public DerivedClass1()
    {
        someData=3;
        someMoreDataStr = "foo";
    }
}

internal class DerivedClass2 : BaseClass
{
    \\This Class will be instantiated after DerivedClass1 And I want to have the 3 And the "foo" In there
    public DerivedClass2()
    {
        \\I want to have the same data initialized earlier here
    }
}

namespace namespace1
{
    internal class Program
    {
        
        static void Main(string[] args)
        {
            BaseClass baseClass = new BaseClass();
            DerivedClass1 = new DerivedClass1(baseClass);//Here I initialize fields in BaseClass
            DerivedClass2 = new DerivedClass2(baseClass);//Here I want the data initialized in BaseClass on the previous line
        }
    }
}