a-a a-b aaa aab aad aak aar aas aau ab- aba abb abd abk abr abs abu ad- ada adb add adk adr ads adu aka akb akd akk akr aks aku ar- ara arb ard ark arr ars aru as- asa asb asd ask asr ass asu au- aua aub aud auk aur aus b-u baa bab bad bak bar bas bau bba bbb bbd bbk bbr bbs bbu bda bdb bdd bdk bdr bds bdu bka bkb bkk bkr bks bra brb brd brk brr brs bru bsa bsb bsd bsk bsr bss bsu bua bub bud buk bur bus buu daa dab dad dak dar das dau dba dbb dbd dbk dbr dbs dbu dda ddb ddd ddk ddr dds ddu dka dkb dkk dkr dks dku dra drb drd drk drr drs dru dsa dsb dsd dsk dsr dss dsu dua dub dud duk dur dus ka- kaa kab kad kak kar kas kau kba kbb kbd kbk kbr kbs kbu kda kdb kdk kdr kds kdu kkb kkk kkr kks kku kra krd krk krr krs kru ksa ksb ksd ksk ksr kss ksu kub kud kuk kur kus kuu ra- raa rab rad rak rar ras rau rba rbb rbd rbk rbr rbs rbu rda rdb rdd rdr rds rdu rkb rkk rks rku rra rrb rrd rrk rrr rrs rru rsa rsb rsd rsk rsr rss rsu rua rub rud ruk rur rus ruu saa sab sad sak sar sas sau sba sbb sbd sbk sbr sbs sbu sda sdb sdd sdk sdr sds sdu sk- ska skb skd skk skr sks sku sr- sra srb srd srk srr srs ss- ssa ssb ssd ssk ssr sss ssu sua sub sud suk sur sus suu ua- uaa uab uad uak uar uas uau uba ubb ubk ubr ubs ubu uda udb udd udk udr uds udu uka ukb ukk ukr uku ur- ura urb urd urk urr urs uru usa usb usd usk usr uss usu uua uur uus uuu