C# How to automatically rename uploaded file if there's already a file with same name

FileUploadHelper.cs

using System.IO;
using System.Linq;
using System.Web;

namespace static class FileUploadHelper
{
	//customize the file size limit accordingly
  private const double MaximumFileSize=10*1024*1024;
  
  public static string UploadFile(HttpPostedFile file)
  {
    if(file.ContentLength <=0 && file.ContentLength > MaximumFileSize)
        thorw new Exception("Error uploading the file");
    
    //your uploads directory path
    var uploadsDirectoryPath="Uploads";
    var absolutePath = HttpContext.Current.Server.MapPath($"~/{uploadsDirectoryPath}");
    
    if (!Directory.Exists(directoryAbsolutePath))
				Directory.CreateDirectory(directoryAbsolutePath);
   
    var suggestedFileName = GetSuggestedFileName(directoryAbsolutePath, file);
	  SaveFile(suggestedFileName, directoryAbsolutePath, file);
    
    //returning the file's relative path (updated path in case file name was updated)
    return Path.Combine(uploadsDirectoryPath, suggestedFileName);
  }
  
  private static string GetSuggestedFileName(string filesDirectory, HttpPostedFile file)
  {
	  var extension = Path.GetExtension(file.FileName);
	  var uploadedFileName = Path.GetFileNameWithoutExtension(file.FileName);
	  var count = Directory.GetFiles(filesDirectory).Select(Path.GetFileNameWithoutExtension)
		  .Count(x => x.StartsWith(uploadedFileName));
	  return count > 0 ? $"{uploadedFileName}_{count+1}{extension}" : $"{uploadedFileName}{extension}";
  }
  
  private static void SaveFile(string fileName, string directoryToSave, HttpPostedFile file)
  {
	  var pathToSave = Path.Combine(directoryToSave, fileName);
	  file.SaveAs(pathToSave);
  }