using System;

//using System.Collections;

using System.Collections.Generic;

using System.IO;

using Aspose.Pdf;

public class Program

{

    public static void Main()

    {

        // input pdf

        Console.WriteLine("input full directory of pdf file");

        var strPath = Console.ReadLine();

        Console.WriteLine(strPath);

        var pdfExists = Directory.Exists(strPath);

        if(!pdfExists)

        {

            Console.WriteLine("not found");

            return;

        }

        // document

        Document doc = new Document(strPath);

        // every page

        foreach(var page in doc.Pages)

        {

            // to save watermarks

            var watermarks = new List<Artifact>();

            // find watermarks

            foreach (Artifact artifact in page.Artifacts)

                if (artifact.Subtype == Artifact.ArtifactSubtype.Watermark)

                    watermarks.Add(artifact);

            // delete watermarks

            foreach(var watermark in watermarks)

                page.Artifacts.Delete(watermark);

        }

        //save pdf

    }

}