program main
      implicit none
      character(200000) :: t
      integer :: i, tlen

      read *, t
      tlen = len_trim(t)

      do i = 1, tlen
        if (t(i:i) == "?") then
            t(i:i) = "D"
        end if
      end do

      print '(a)', t(1:tlen)

end program main
