object Main extends App {
	val Array(a, b) = scala.io.StdIn.readLine.split(" ")

	val ans = (a, b) match {
		case ("H", "H") => "H"
		case ("H", "D") => "D"
		case ("D", "H") => "D"
		case ("D", "D") => "H"
	}

	println(ans)
}
