import java.util.Scanner
import java.io.PrintWriter

object Main {
  def main(args: Array[String]): Unit = {
    val sc = new Scanner(System.in)
    val pw = new PrintWriter(System.out)

    val n = sc.nextInt()
    val s = sc.next()
    val sb = new StringBuilder
    for (i <- 0 until s.length) {
      sb.append(('A' + (s(i) - 'A' + n) % 26).toChar)
    }
    pw.println(sb)

    pw.flush()
  }
}