atcoder#NOMURA2020B. Postdocs

Postdocs

Score : 200200 points

Problem Statement

For a string SS consisting of the uppercase English letters P and D, let the doctoral and postdoctoral quotient of SS be the total number of occurrences of D and PD in SS as contiguous substrings. For example, if S=S = PPDDP, it contains two occurrences of D and one occurrence of PD as contiguous substrings, so the doctoral and postdoctoral quotient of SS is 33.

We have a string TT consisting of P, D, and ?.

Among the strings that can be obtained by replacing each ? in TT with P or D, find one with the maximum possible doctoral and postdoctoral quotient.

Constraints

  • 1T2×1051 \leq |T| \leq 2 \times 10^5
  • TT consists of P, D, and ?.

Input

Input is given from Standard Input in the following format:

TT

Output

Print one string with the maximum possible doctoral and postdoctoral quotient among the strings that can be obtained by replacing each ? in TT with P or D. If there are multiple such strings, you may print any of them.

PD?D??P
PDPDPDP

This string contains three occurrences of D and three occurrences of PD as contiguous substrings, so its doctoral and postdoctoral quotient is 66, which is the maximum doctoral and postdoctoral quotient of a string obtained by replacing each ? in TT with P or D.

P?P?
PDPD