main = getLine >>= putStrLn . f . map read . words
f [x, y, x', y'] =
  r dx
    ++ u dy
    ++ l dx
    ++ d (dy + 1)
    ++ r (dx + 1)
    ++ u (dy + 1)
    ++ l 1
    ++ u 1
    ++ l (dx + 1)
    ++ d (dy + 1)
    ++ r 1
 where
  [l, r, d, u] = map (flip replicate) "LRDU"
  (dy, dx)     = (y' - y, x' - x)

