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 C# (.NET Core 3.1.201) (judge verdict: Accepted)

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Runtime.CompilerServices;
using System.Text;
using static System.Console;
using static System.Math;

namespace Atcoder
{
    class Program
    {
        static StreamWriter sw = new StreamWriter(OpenStandardOutput()) { AutoFlush = false };
        static void Main(string[] args)
        {
            try
            {
                SetOut(sw);
                Solve.Answer();
                Out.Flush();
            }
            catch (Exception ex)
            {
                WriteLine(ex.ToString());
            }
        }
    }

    public class Solve
    {
        public static void Answer()
        {
            var s = ReadLine();

            var a = s.Replace("?", "D");
            //int cnt = 0;
            //bool f = false;
            //for (int i = 0; i < a.Length; i++)
            //{
            //    if (a[i] == 'D')
            //    {
            //        cnt++;
            //        if (f)
            //            cnt++;
            //        f = false;

            //    }
            //    else if (a[i] == 'P')
            //    {
            //        f = true;
            //    }
            //}
            WriteLine(a);
        }

        public class IO
        {
            #region Input
            public static int RInt => int.Parse(ReadLine());
            public static long RLong => long.Parse(ReadLine());
            public static double RDouble => double.Parse(ReadLine());

            public static string[] RSString => ReadLine().Split();
            public static int[] RSInt => ReadLine().Split().Select(s => int.Parse(s)).ToArray();
            public static long[] RSLong => ReadLine().Split().Select(s => long.Parse(s)).ToArray();
            public static double[] RSDouble => ReadLine().Split().Select(s => double.Parse(s)).ToArray();
            #endregion

            #region Output
            public static void OutJoinSpace<T>(IEnumerable<T> list) => WriteLine(string.Join(" ", list));
            public static void WriteLineYes_or_No(bool flag) => WriteLine(flag ? "Yes" : "No");
            public static void WriteLineYES_or_NO(bool flag) => WriteLine(flag ? "YES" : "NO");
            #endregion
        }

        public class Mod
        {
            #region
            private readonly static long M = 1000000007;

            public static long Add(long a, long b) => (a * b) % M;
            public static long Sub(long a, long b) => (a - b) % M >= 0 ? (a - b) % M : (a - b) % M + M;
            public static long Multi(long a, long b) => (a * b) % M;
            #endregion
        }
    }
}