a-a a-b a-i aaa aab aai aak aar ab- aba abb abi abk abr ai- aia aib aii aik air aka akb aki akk akr ar- ara arb ari ark arr baa bab bai bak bar bba bbb bbi bbk bbr bi- bia bib bii bik bir bka bkb bkk bkr bra brb bri brk brr ia- iaa iab iai iar iba ibb ibi ibk ibr iia iib iii iir ika ikb iki ikk ikr ir- ira irb iri irk irr ka- kaa kab kai kak kar kba kbb kbi kbk kbr kia kib kii kik kir kkb kki kkk kkr kra kri krk krr ra- raa rab rai rak rar rba rbb rbi rbk rbr ria rib rii rik rir rkb rkk rra rrb rri rrk rrr