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)

a=gets.chomp.chars
idx = []
a.select.with_index{|b,i| idx << i if b == '?' }
y = a.join.count('?')
c = []

z = [1,2]
x = z.repeated_permutation(y).to_a

x.each{|xx|
  xx.each_with_index{|xxx,k|
    if xxx == 1
      a[idx[k]] = 'P'
    else
      a[idx[k]] = 'D'
    end
  }
  c << a.join
}

#p x
#p c
cc_cnt = []
c.each{|cc|
  cc_d_cnt = cc.count('D')
  cc_pd_cnt = cc.scan('PD').length
  cc_cnt << cc_d_cnt + cc_pd_cnt
}

puts c[cc_cnt.index(cc_cnt.max)]