Problem:
Score : 200 points

Problem 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.

Constraints

1 \leq |T| \leq 2 \times 10^5

T consists of P, D, and ?.

Input

Input is given from Standard Input in the following format:

T

Output

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.

Sample Input 1

PD?D??P

Sample Output 1

PDPDPDP

This string contains three occurrences of D and three occurrences of PD as contiguous substrings, so its doctoral and postdoctoral quotient is 6, which is the maximum doctoral and postdoctoral quotient of a string obtained by replacing each ? in T with P or D.

Sample Input 2

P?P?

Sample Output 2

PDPD

Solution in Ruby (2.7.1) (judge verdict: Time Limit Exceeded)

t=gets.chomp.chars
q_cnt=t.count('?')
pts=['P','D'].repeated_permutation(q_cnt-1).to_a
ans=0
res = ""
tmp = t.map do |j|
        if j=='?'
          'D'
        else
          j
        end
end
cmp = tmp.count('D')+tmp.count('PD')
if ans < cmp
  ans = cmp
  res = tmp.join
end

=begin
pts.each do |i|
  tmp = t.map do |j|
          if j=='?'
            i.shift
          else
            j
          end
  end
  cmp = tmp.count('D')+tmp.count('PD')
  if ans < cmp
    ans = cmp
    res = tmp.join
  end
end
=end
puts res