let stripHtmlTags (input: seq<char>) =
    input
    |> Seq.fold
        (fun (flag,sb:(System.Text.StringBuilder)) c -> 
            match c with 
            |'<' -> true,sb
            |'>' -> false,sb
            |n -> 
                if flag then flag,sb
                else (flag, sb.Append(n))
        )
        (false,System.Text.StringBuilder())
    |> (fun (_,sb) -> sb.ToString())