open System

let n = stdin.ReadLine() |> int

let rec loop l r cnt =
    if cnt = 0 then
        l @ List.rev r
        |> String.Concat
    else
        let [| t; s |] =
            stdin.ReadLine().Split()
        if t = "0" then
            loop l (s :: r) (cnt - 1)
        else
            loop (s :: l) r (cnt - 1)

loop [] [] n
|> printfn "%s"