import java.util.*

fun main(args: Array<String>) {
    val scanner = Scanner(System.`in`)
    val i = scanner.nextInt()
    val s = scanner.next()

    val r = s.toCharArray()
        .map { it.plus(i) }
        .map {
            if (it <= 'Z') {
                it
            } else {
                it - 26
            }
        }
        .joinToString("")

    println(r)
}
