GetSingle Flile From SharePoint Library

using Microsoft.SharePoint.Client
using Microsoft.SharePoint
using Microsoft.SharePoint.Client.UserProfiles
public void getSingleFiledFromLibrary()
{
    ClientContext ctx = new ClientContext(
        "URL");
    ctx.Credentials = new NetworkCredential(
        "userid", "pwd", "domain");
    Web web = ctx.Web;
    try
    {
        Microsoft.SharePoint.Client.File file =
            web.GetFileByServerRelativeUrl(
                "/LibraryName/filename.fileExtension"
            );
        //ctx.Load(web);
        ctx.Load(file);
        ctx.ExecuteQuery();
    }
    catch (Exception ex)
    {
        Console.WriteLine(ex.Message);
    }
}