let () = 
        Scanf.scanf "%s\n" (
                fun s -> 
                        Scanf.scanf "%s" (
                                fun t -> 
                                        let sub = String.sub t 0 (String.length s) in
                                                if s = sub then
                                                        "Yes"
                                                else
                                                        "No"
                        )
        ) |> Printf.printf "%s\n"