a-a a-b a-i aaa aab aai aak aap aar ab- aba abb abi abk abp abr ai- aia aib aii aik aip air aka akb aki akk akp akr ap- apa apb api apk app apr ar- ara arb ari ark arp arr b-p baa bab bai bak bap bar bba bbb bbi bbk bbp bbr bi- bia bib bii bik bip bir bka bkb bkk bkp bkr bpa bpb bpi bpp bpr bra brb bri brk brp brr ia- iaa iab iai iap iar iba ibb ibi ibk ibp ibr iia iib iii iip iir ika ikb iki ikk ikr ipa ipb ipi ipp ipr ir- ira irb iri irk irp irr ka- kaa kab kai kak kap kar kba kbb kbi kbk kbp kbr kia kib kii kik kip kir kkb kki kkk kkp kkr kpa kpi kpk kpp kpr kra kri krk krp krr p-p paa pab pai pak pap par pba pbb pbi pbk pbp pbr pia pib pii pik pip pir pka pkb pki pkp pkr ppa ppb ppi ppk ppp ppr pra prb pri prk prp prr ra- raa rab rai rak rap rar rba rbb rbi rbk rbp rbr ria rib rii rik rip rir rkb rkk rkp rpa rpb rpi rpk rpp rpr rra rrb rri rrk rrp rrr