How to compare PDFs using C#

// Composing PDFs distinctions report

// Instantiate Comparer with path to a first file
using (Comparer comparer = new Comparer("source.pdf"))
{
    // Append one or more PDFs to comparison
	comparer.Add("file_to_compare_1.pdf");
    comparer.Add("file_to_compare_2.pdf");
    comparer.Add("file_to_compare_3.pdf");

    // Result report to be analyzed
    comparer.Compare("result.pdf"); 
}