let strArray = readLine()!.map{$0}
for (i,str) in strArray.enumerated(){
    var code = String(str).unicodeScalars.first!.value
    var usa = Int(code) - (i+1) % 26
    if usa < 65{
        usa = usa + 26
    }
    let chrStr = Character(UnicodeScalar(usa)!)
    print(chrStr,terminator:"")
}
print()