output_description: Print one string with the maximum possible doctoral and postdoctoral quotient
  among the strings that can be obtained by replacing each `?` in T with `P` or
  `D`. If there are multiple such strings, you may print any of them.
  
  * * *
input_description: Input is given from Standard Input in the following format:
  
      
      
      T
attempt: li = list(input())
  lis = li.copy()
  count1 = 0
  count2 = 0
  for i in range(0, len(li)):
      if li[i] == "P":
          try:
              if li[i + 1] != "P":
                  count1 += 1
                  li[i + 1] = "D"
          except IndexError:
              continue
      elif li[i] == "?":
          li[i] = "P"
      else:
          continue
  
  for i in range(0, len(lis)):
      if lis[i] == "P":
          try:
              if lis[i + 1] != "P":
                  count2 += 1
                  lis[i + 1] = "D"
          except IndexError:
              continue
      elif lis[i] == "?":
          lis[i] = "D"
  
      else:
          continue
  
  
  c = li.count("D")
  d = lis.count("D")
  a = c + count1
  b = d + count2
  if a >= b:
      for i in li:
          print(i, end="")
  else:
      for i in lis:
          print(i, end="")
  
problem_description: Statement
  
  For a string S consisting of the uppercase English letters `P` and `D`, let
  the _doctoral and postdoctoral quotient_ of S be the total number of
  occurrences of `D` and `PD` in S as contiguous substrings. For example, if S =
  `PPDDP`, it contains two occurrences of `D` and one occurrence of `PD` as
  contiguous substrings, so the doctoral and postdoctoral quotient of S is 3.
  
  We have a string T consisting of `P`, `D`, and `?`.
  
  Among the strings that can be obtained by replacing each `?` in T with `P` or
  `D`, find one with the maximum possible doctoral and postdoctoral quotient.
samples: [{"input": "PD?D??P", "output": "PDPDPDP\n    \n\nThis string contains three occurrences of `D` and three occurrences of `PD` as\ncontiguous substrings, so its doctoral and postdoctoral quotient is 6, which\nis the maximum doctoral and postdoctoral quotient of a string obtained by\nreplacing each `?` in T with `P` or `D`.\n\n* * *"}, {"input": "P?P?", "output": "PDPD"}]