
solve a b
  | a == "H" && b == "H" = "H"
  | a == "H" && b == "D" = "D"
  | a == "D" && b == "H" = "D"
  | a == "D" && b == "D" = "H"

main = do
  s <- getLine
  let [a, b] = words s in
    putStrLn $ solve a b
