Scanf.scanf "%s" (fun s ->
    let n = String.length s in
    let rec loop i mode acc =
        if i = n then (if mode = 1 then acc ^ "a" else acc) else
            match mode, s.[i] with
            | 0, 'a' -> loop (i + 1) 1 acc
            | 0, c   -> loop (i + 1) 0 (Printf.sprintf "%s%c" acc c)
            | 1, 'o' -> loop (i + 1) 0 (acc ^ "ki")
            | 1, 'a' -> loop (i + 1) 1 (acc ^ "a")
            | _, c   -> loop (i + 1) 0 (Printf.sprintf "%sa%c" acc c)
    in
    loop 0 0 "" |> print_endline
)