main = putStrLn . solve . map read . words =<< getContents

solve :: [Int] -> String
solve [sx, sy, tx, ty] =
    let
        x = tx - sx
        y = ty - sy
    in (replicate x 'R') ++ (replicate y 'U') ++ (replicate x 'L') ++ (replicate (y+1) 'D')
        ++ (replicate (x+1) 'R') ++ (replicate (y+1) 'U') ++ "LU" ++ (replicate (x+1) 'L') ++ (replicate (y+1) 'D') ++ "R"
