import java.io.{BufferedReader,InputStreamReader}
object no18{
    def main(args:Array[String]):Unit={
        val br = new BufferedReader(new InputStreamReader(System.in))
        val s = br.readLine().zipWithIndex
        val res = s.map{
             case (c,i) => 
             val a = (((c-'A')-(i+1))%26+26)%26
             (a+'A').toChar
        }
        res.foreach(print _)
        println()
    }
}