Formating lost while programmatically pasting slides from multiple presentations into a single presentation using C# Interop

Question

I am trying to paste multiple slides from a different PPTs in an existing PPT. I could paste multiple slides but issue is formating of slides is not preserved. my code is as follows

Presentation Pres = pptApp.Presentations.Open("Original.pptx", MsoTriState.msoFalse, MsoTriState.msoFalse, MsoTriState.msoFalse);
int counter = 1;
//slideNumbers is a list of slide numbers or position at which we are going to insert the slide in original file
                foreach (var number in slideNumbers)
                {
                    if (pres != null)
                    {                                                       
                        pres.Slides[number].Delete();
                        pres.Slides.InsertFromFile("temp.pptx", number- 1, counter, counter);                         
                        counter++;                        
                    }
                }
                              }
            if (pres != null)
            {
                pres.SaveAs("Final.pptx");
                pres.Close();
                Marshal.ReleaseComObject(pres);
            }

I found the VBA equivalent of what I'm searching for, but couldn't convert it into C#. (Refer: Programmatically combine slides from multiple presentations into a single presentation)

I need solution in c#. Thank you !