[<AutoOpen>]
module Program

open System

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

[<EntryPoint>]
let main _ =
    let N = read int
    let S = (read string).ToCharArray()

    let bs = ['A'..'Z'] @ ['A'..'Z'] |> Array.ofList

    let f c =
        let i = Array.findIndex ((=) c) bs
        bs.[i + N]

    let ans = Array.map f S

    printfn "%s" (String.Join("", ans))
    0