using System;

public class Program

{

    public static void Main()

    {

        Console.WriteLine(System.IO.Path.Combine("//", "C:/test/path/string/test"));

        Console.WriteLine(System.IO.Path.Combine("//test/cats", "/test"));

        Console.WriteLine(System.IO.Path.Combine("//test/cats", "/test"));

        Console.WriteLine(System.IO.Path.Combine("C:/test/cats", "/test"));     

        Console.WriteLine(System.IO.Path.Combine("C:/test/cats", "C:"));

​

    }

}