C# code -Compare 2 list and export the difference in excel

Question

I have twp pdfs.I want to compare it.For that i converts 2 pdf into 2 lists.I want to compare the 2 lists and export the difference as 2 columns in excel.Could you please help me to find the  c# code for it?Please find the below incomplete code?

public static void CompareTwoPDF(string FirstPDF, string SecondPDF)

{

if (File.Exists(FirstPDF) && File.Exists(SecondPDF))

{

PdfReader reader = new PdfReader(SecondPDF);

for (int page = 1; page <= reader.NumberOfPages; page++)

{

ITextExtractionStrategy strategy = new SimpleTextExtractionStrategy();

FirstFile += PdfTextExtractor.GetTextFromPage(reader, page, strategy);

}

PdfReader reader1 = new PdfReader(FirstPDF);

for (int page = 1; page <= reader.NumberOfPages; page++)

{

ITextExtractionStrategy strategy = new SimpleTextExtractionStrategy();

SecondFile += PdfTextExtractor.GetTextFromPage(reader1, page, strategy);

}

}

else

{

Console.WriteLine("Files does not exist.");

}

List<string> File1diff;

List<string> File2diff;

IEnumerable<string> file1 = FirstFile.Trim().Split('\r', '\n');

IEnumerable<string> file2 = SecondFile.Trim().Split('\r', '\n');

File1diff = file1.ToList();

File2diff = file2.ToList();

}

}

}

}