package main
import "fmt"
func main(){
    var s, result string
    fmt.Scan(&s)
    for k, v := range s {
        i := int(v)
        rn := i - (k + 1)
        for rn < 65 {
            rn += 26
        }
        result += string(rn)
    }
    fmt.Println(result)
}