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: Accepted)

t = gets.chomp.split('')

PD = []
D = []

t.each do |i|
  if i == "?"
    PD << "P"
  elsif i != "?"
    PD << i
  end
end

t.each do |k|
  if k == "?"
    D << "D"
  elsif k != "?"
    D << k
  end
end

PD_count1 = PD.join.scan("PD").length
PD_count2 = PD.join.scan("D").length

D_count1 = D.join.scan("D").length
D_count2 = D.join.scan("PD").length

print (PD_count1 + PD_count2) >= (D_count1 + D_count2) ? PD.join : D.join