program main
    implicit none
    character t*200000
    character, allocatable :: s(:)
    integer i,n

    read(*,*) t
    n = len_trim(t)
    allocate(s(n))
    do i = 1,n
        if(t(i:i) == "?") then
            s(i:i) = "D"
        else
            s(i:i) = t(i:i)
        end if
    end do

    write(*,*) s

end program

