fun solve(n:Int, s:String){
    val alp = "abcdefghijklmnopqrstuvwxyz"
    var ans = ""

    for(i in 0 until s.length){
        val idx = alp.indexOf(s[i].toLowerCase())
        ans += alp[(idx+n)%26]
    }

    println(ans.toUpperCase())
}


fun main(){
    val n = readLine()!!.toInt()
    val s = readLine()!!
    solve(n,s)
}