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 Python (3.8.2) (judge verdict: Wrong Answer)

S = input()
ans = ""
N = len(S)
now = "D"
for i in range(N):
  if(i != N-1):
    if(S[i] == "D" or S[i] == "P"):
      ans += S[i]
    elif(S[i] == "?"):
      if(S[i+1] == "P"):
        ans += "D"
      elif(S[i+1] == "D"):
        ans += "P"
      else: #後ろが"?"ならば
        if(i == 0):
          ans += "D"
        else:
          if(S[i-1] == "P"):
            ans += "D"
          else:
            ans += "D" #あやしい
  else:
    if(S[i] == "?"):
      ans += "D"
    else:
      ans += S[i]
      
print(ans)