a-a a-b a-i a-z aaa aab aai aap aar aaz ab- aba abb abi abp abr abz ai- aia aib aii aip air aiz ap- apa apb api app apr ar- ara arb ari arp arr arz az- aza azb azi azp azz b-p baa bab bai bap bar baz bba bbb bbi bbp bbr bi- bia bib bii bip bir biz bpa bpb bpi bpp bpr bra brb bri brp brr brz bza bzp bzr bzz ia- iaa iab iai iap iar iaz iba ibb ibi ibp ibr ibz iia iib iii iip iir ipa ipb ipi ipp ipr ir- ira irb iri irp irr iza izi izz p-p paa pab pai pap par paz pba pbb pbi pbp pbr pbz pia pib pii pip pir piz ppa ppb ppi ppp ppr ppz pra prb pri prp prr prz pzp ra- raa rab rai rap rar raz rba rbb rbi rbp rbr ria rib rii rip rir riz rpa rpb rpi rpp rpr rpz rra rrb rri rrp rrr rza rzb zaa zab zai zap zar zaz zbb zbr zia zib zip zir ziz zpi zpp zpr zrp zzr zzz