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 PyPy3 (7.3.0) (judge verdict: Accepted)

import sys
from io import StringIO
import unittest


def resolve():
    t = list(input())

    if t[0] == '?':
        t[0] = 'D'

    for i in range(1, len(t) - 1):
        if t[i] == '?':
            if t[i - 1] == 'P':
                t[i] = 'D'
            else:
                if t[i + 1] == '?':
                    t[i] = 'P'
                    t[i + 1] = 'D'
                elif t[i + 1] == 'D':
                    t[i] = 'P'
                else:
                    t[i] = 'D'

    if t[-1] == '?':
        t[-1] = 'D'

    print(''.join(t))



class TestClass(unittest.TestCase):
    def assertIO(self, input, output):
        stdout, stdin = sys.stdout, sys.stdin
        sys.stdout, sys.stdin = StringIO(), StringIO(input)
        resolve()
        sys.stdout.seek(0)
        out = sys.stdout.read()[:-1]
        sys.stdout, sys.stdin = stdout, stdin
        self.assertEqual(out, output)

    def test_入力例_1(self):
        input = """PD?D??P"""
        output = """PDPDPDP"""
        self.assertIO(input, output)

    def test_入力例_2(self):
        input = """P?P?"""
        output = """PDPD"""
        self.assertIO(input, output)


if __name__ == "__main__":
    # unittest.main()
    resolve()