open System

let padBoth c w (s : string) = s.PadLeft((w + s.Length) / 2, c).PadRight(w, c)

let asciiPairs n inGap outGap =
    if n = 0 then "1" else String.Join(String.replicate outGap "_", Seq.replicate n ("1" + (String.replicate inGap "_") + "1"))

let rec treeLines lvl maxDrawLvl maxLvl w cnt inPairs outPairs = seq {
    for y in [1 .. cnt] do
        yield match y with
                | _ when lvl > maxDrawLvl -> ""
                | _ when y <= cnt / 2 -> asciiPairs inPairs (2 * cnt - 1) (2 * cnt - 1)
                | _                   -> asciiPairs outPairs (2 * y - cnt - 1) (3 * cnt - 2 * y - 1)
                |> padBoth '_' w

    yield! if lvl >= maxLvl then Seq.empty 
        else (treeLines (lvl + 1) maxDrawLvl maxLvl w (cnt / 2) outPairs (outPairs * 2))
}

let asciiTree n w = treeLines 1 n 6 w 32 0 1 |> Seq.rev

asciiTree (Console.ReadLine() |> int) 100 |> Seq.iter (printfn "%s")