How to serialize field of type class as main object fields with NewtonSoft json?

Assume that i have these classes:

public class A
{
    public int aField;
    public C c;
}

public class B
{
    public string bField;
    public C c;
}

public class C
{
    public string cField;
}

Now, i want to use JSON.Net JsonConverter annotation to serialize C as below when i want to load A or B objects. for example something like this:

[JsonConverter(typeof(JsonConverterCustomImpl))]
public class C
{
    public string cField;
}

and the result of serialized A or B objects should be like this:

// A object
{
   aField: 0,
   cField: ''
}

// B object
{
   bField: 0,
   cField: ''
}

I dont know how shoud=ld i implement the JsonConverterCustomImpl class.