open System
let R T = stdin.ReadLine()|> T
let RS T = stdin.ReadLine().Split()|>Array.map T
let Mod = (1e9|>int64)+7L
[<EntryPoint>]
let main argv =
    let N = R int
    let S = R string
    for c in S do
        c
        |>int
        |>fun c -> (((c - ('A'|>int) + N)%26)+('A'|>int))
        |>char
        |>stdout.Write
    stdout.WriteLine ""
    0
