output_description: Print a string S that represents a shortest path for Dolphin.  
  The i-th character in S should correspond to his i-th movement.  
  The directions of the movements should be indicated by the following
  characters:
  
    * `U`: Up
    * `D`: Down
    * `L`: Left
    * `R`: Right
  
  If there exist multiple shortest paths under the condition, print any of them.
  
  * * *
input_description: The input is given from Standard Input in the following format:
  
      
      
      sx sy tx ty
attempt: #! /usr/bin/python
  # Back and Forth
  
  """
      −1000≦sx<tx≦1000
      −1000≦sy<ty≦1000
      sx,sy,tx,ty
      は整数である。
  """
  
  test_mode = False
  
  sx, sy, tx, ty = map(int, input().split())
  dx = tx - sx
  dy = ty - sy
  abs_dx = abs(dx)
  abs_dy = abs(dy)
  
  if test_mode:
      print("dx = {}".format(dx))
      print("dy = {}".format(dy))
      print("abs_dx = {}".format(abs_dx))
      print("abs_dy = {}".format(abs_dy))
  
  
  def course_type(x, y):
      """
      x, y について
          0: x,y 両方が でない
          1: x   だけが 0
          2: y   だけが 0
          3: x,y 両方が 0
      を返す。入力は絶対値でよろしく。
      """
      if x != 0 and y != 0:
          return 0
      if x == 0 and y != 0:
          return 1
      if x != 0 and y == 0:
          return 2
      return 3
  
  
  def course_temp(x, y):
      """
      とりあえず (0, 0)→(x, y) の2往復のしかたを返す関数。
      x,y >= 0 とすること。※第1象限で考えるため
      """
  
      s = ""
      flag = course_type(x, y)
  
      if flag == 0:  # 2点が線分上にない場合
          # ここから 1往復目
          for _ in range(x):
              s += "R"
          for _ in range(y):
              s += "U"
          for _ in range(x):
              s += "L"
          for _ in range(y):
              s += "D"
          # ここまで 1往復目
          # ここから 2往復目
          s += "U"
          for _ in range(x + 1):
              s += "R"
          for _ in range(y + 1):
              s += "U"
          s += "L"
          s += "U"
          for _ in range(x + 1):
              s += "L"
          for _ in range(y + 1):
              s += "D"
          s += "R"
          # ここまで 2往復目
  
      elif flag == 1:
          # ここから 1往復目
          for _ in range(y + 1):
              s += "U"
          s += "L"
          s += "L"
          for _ in range(y + 2):
              s += "D"
          s += "R"
          s += "R"
          s += "U"
          # ここまで 1往復目
          # ここから 2往復目
          s += "R"
          for _ in range(y):
              s += "U"
          s += "L"
          s += "L"
          for _ in range(y):
              s += "D"
          s += "R"
          # ここまで 2往復目
  
      elif flag == 2:
          # ここから 1往復目
          for _ in range(y + 1):
              s += "R"
          s += "U"
          s += "U"
          for _ in range(y + 2):
              s += "L"
          s += "D"
          s += "D"
          s += "R"
          # ここまで 1往復目
          # ここから 2往復目
          s += "D"
          for _ in range(y):
              s += "R"
          s += "U"
          s += "U"
          for _ in range(y):
              s += "L"
          s += "D"
          # ここまで 2往復目
  
      else:
          pass
  
      return s
  
  
  def convert(s):
      """
      dx, dy の符号に応じて 文字列s を変換して返す関数
      """
      if dx >= 0:
          pass
      else:
          s.translate(
              str.maketrans(
                  "RL",
                  "LR",
              )
          )  # x方向の移動を反転
      if dy >= 0:
          pass
      else:
          s.translate(
              str.maketrans(
                  "UD",
                  "DU",
              )
          )  # y方向の移動を反転
  
      return s
  
  
  def main():
      """
      全体の処理を実行する関数
      """
      course = course_temp(abs_dx, abs_dy)
      if test_mode:
          print("course:", course)
  
      course = convert(course)
      if test_mode:
          print("course:", course)
      print(course)
  
  
  if __name__ == "__main__":
      main()
  
  
  """
  参考
      Pythonで文字列を置換（replace, translate, re.sub, re.subn）
      https://note.nkmk.me/python-str-replace-translate-re-sub/
  """
  
problem_description: Statement
  
  Dolphin resides in two-dimensional Cartesian plane, with the positive x-axis
  pointing right and the positive y-axis pointing up.  
  Currently, he is located at the point (sx,sy). In each second, he can move up,
  down, left or right by a distance of 1.  
  Here, both the x\- and y-coordinates before and after each movement must be
  integers.  
  He will first visit the point (tx,ty) where sx < tx and sy < ty, then go back
  to the point (sx,sy), then visit the point (tx,ty) again, and lastly go back
  to the point (sx,sy).  
  Here, during the whole travel, he is not allowed to pass through the same
  point more than once, except the points (sx,sy) and (tx,ty).  
  Under this condition, find a shortest path for him.
samples: [{"input": "0 0 1 2", "output": "UURDDLLUUURRDRDDDLLU\n    \n\nOne possible shortest path is:\n\n  * Going from (sx,sy) to (tx,ty) for the first time: (0,0) \u2192 (0,1) \u2192 (0,2) \u2192 (1,2)\n  * Going from (tx,ty) to (sx,sy) for the first time: (1,2) \u2192 (1,1) \u2192 (1,0) \u2192 (0,0)\n  * Going from (sx,sy) to (tx,ty) for the second time: (0,0) \u2192 (-1,0) \u2192 (-1,1) \u2192 (-1,2) \u2192 (-1,3) \u2192 (0,3) \u2192 (1,3) \u2192 (1,2)\n  * Going from (tx,ty) to (sx,sy) for the second time: (1,2) \u2192 (2,2) \u2192 (2,1) \u2192 (2,0) \u2192 (2,-1) \u2192 (1,-1) \u2192 (0,-1) \u2192 (0,0)\n\n* * *"}, {"input": "-2 -2 1 1", "output": "UURRURRDDDLLDLLULUUURRURRDDDLLDL"}]