a-a a-b a-i aaa aab aai aao aar aau aax ab- aba abb abi abo abr abu abx ai- aia aib aii aio air aiu aix aoa aob aoi aoo aor aou aox ar- ara arb ari aro arr aru arx au- aua aub aui auo aur aux ax- axa axi axo axr axx b-u baa bab bai bao bar bau bax bba bbb bbi bbo bbr bbu bbx bi- bia bib bii bio bir biu bix boa bob boi boo bor bou box bra brb bri bro brr bru brx bua bub bui buo bur buu bux bxb bxi bxo bxx ia- iaa iab iai iao iar iau iba ibb ibi ibo ibr ibu ibx iia iib iii iio iir iiu iix io- ioa iob ioi ioo ior iou ir- ira irb iri iro irr iru irx iu- iua iub iui iur ixi o-i oaa oab oai oao oar oau oax ob- oba obb obi obo obr obu obx oia oib oii oio oir oiu oo- ooa oob ooi ooo oor oox or- ora orb ori oro orr oru orx ou- oua oui ouo our ox- oxa oxb oxi oxo oxx ra- raa rab rai rao rar rau rax rba rbb rbi rbo rbr rbu rbx ria rib rii rio rir rix roa rob roi roo ror rou rox rra rrb rri rrr rru rua rub rui ruo rur ruu rux rxr ua- uaa uab uai uao uar uau uba ubb ubi ubo ubr ubu ubx uia uib uii uio uir uiu uoa uob uoo uor uox ur- ura urb uri uro urr uru urx uua uur uuu uxb uxo uxr uxu xaa xar xau xbr xbx xia xii xio xiu xix xoa xoi xoo xor xox xrx xui xxi xxo xxx