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: Runtime Error)

t = input()
if(t[0] == '?'):
    if  (t[1] == 'D'): t = "".join(['P' , t[1:]])
    elif(t[1] == '?'): t = "".join(['PD', t[2:]])
    else:              t = "".join(['D' , t[1:]])
if(t[-1] == '?'):
    t = "".join([t[:-1], 'D'])
for i in range(len(t)-1):
    if(t[i] == '?'):
        if(t[i-1] == 'P'):    t = "".join([t[:i], 'D' , t[i+1:]])
        elif(t[i+1] == 'D'):  t = "".join([t[:i], 'P' , t[i+1:]])
        elif(t[i+1] == 'P'):  t = "".join([t[:i], 'D' , t[i+1:]])
        elif(t[i+1] == '?'):  t = "".join([t[:i], 'PD', t[i+2:]])
print(t)