define interface method with different parameters in C# -

interface parentinterface {    public string methoda(/*define parameters name , datatype*/); } 

and

public class childa : parentinterface {   public string methoda(string a, int b, string c, long d){} }  public class childb : parentinterface {    public string methoda(int e, string f, string g){} } 

i want define interface method's parameters name , data type

you have 2 different methods

public string methoda(string a, int b, string c, long d){} 

and

public string methoda(int e, string f, string g){} 

that represent 2 different contracts childa , childb respectively. cannot define interface single methoda fits both definitions. seek not possible.

note define both overloads in interface, each class implementing interface have implement both overloads.