[<AutoOpen>]
module Program

open System

let read f = stdin.ReadLine() |> f
let reads f = stdin.ReadLine().Split() |> Array.map f

[<EntryPoint>]
let main _ =
    let N = read int
    let [|S;T|] = reads string |> Array.map Seq.toArray
    for s, t in Array.zip S T do
        printf "%c%c" s t
    printfn ""
    0