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: a, b, c, d = map(int, input().split())
  Str = ""
  U_1st_num = d - b
  for i in range(U_1st_num):
      Str = Str + "U"
  R_1st_num = c - a
  for i in range(R_1st_num):
      Str = Str + "R"
  D_2nd_num = d - b
  for i in range(D_2nd_num):
      Str = Str + "D"
  L_2nd_num = c - a
  for i in range(L_2nd_num):
      Str = Str + "L"
  Str = Str + "L"
  for i in range(U_1st_num + 1):
      Str = Str + "U"
  for i in range(R_1st_num + 1):
      Str = Str + "R"
  Str = Str + "D"
  Str = Str + "R"
  for i in range(D_2nd_num + 1):
      Str = Str + "D"
  for i in range(L_2nd_num + 1):
      Str = Str + "L"
  Str = Str + "U"
  print(Str)
  
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"}]