#include<stdio.h>
#include<stdlib.h>
#include<string.h>
#include<math.h>
#define ll long long



int main(){
  char t;
  while(scanf("%c",&t)){
    if(t=='?'){
      printf("D");}
    else{
      printf("%c",t);}}
  //printf("%lu\n",strlen(t));
  //printf("%s\n",t);
  
  return 0;
}
