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 JavaScript (Node.js 12.16.1) (judge verdict: Wrong Answer)

function Main(str) {
  	str = str.split("");
    let count = 0;

  	str.forEach((s) => {
    	if(s === 'D') {
        	count++;
        }
    });
  	let foundP = false;
  	let foundPD = false;
	for(let i=0;i<str.length;i++) {
      	if(str[i] === 'P') {
        	foundP = true;
        }
      
      	if(str[i] === 'D' & str[i-1] === 'P') {
        	foundPD = true;
          	count++;
        }
      

      	if(str[i] === '?') {
        	if(!foundP) {
            	str[i] = 'P';
      
              	continue;
            }
          	if(count > 0 && count % 3 === 0) {
            	str[i] = 'P';
              	continue;
            }
          	
            str[i] = 'D';
          	count++;
          
          
        }
    	
    }
  	
  	console.log(str.join(""));
  	
}

let input = require('fs').readFileSync('/dev/stdin', 'utf8');
Main(input);