program abc049c
    use,intrinsic :: iso_fortran_env
    implicit none
    character(100000):: s
    character(:),allocatable:: dream, dreamer, erase, eraser
    integer(int32):: i


    dream = 'dream'
    dreamer = 'dreamer'
    erase = 'erase'
    eraser = 'eraser'

    read*, s

    do while(len_trim(s) > 0)

        i = index(s,dream//eraser)
        if (i > 0) then
            s=s(12:)
            cycle
        end if
        i = index(s,dream//erase)
        if (i > 0) then
            s=s(11:)
            cycle
        end if

        i = index(s,dreamer)
        if (i > 0) then
            s = s(8:)
            cycle
        end if

        i = index(s,dream)
        if (i > 0) then
            s = s(6:)
            cycle
        end if

        i = index(s,eraser)
        if (i > 0) then
            s = s(7:)
            cycle
        end if

        i = index(s,erase)
        if (i > 0) then
            s = s(6:)
            cycle
        end if

        print'(a)', 'NO'
        stop
    end do
    print'(a)', 'YES'
end program abc049c