a-a a-b a-i aaa aab aad aai aar aas ab- aba abb abd abi abr abs ad- ada adb add adi adr ads ai- aia aib aid aii air ais ar- ara arb ard ari arr ars as- asa asb asd asi asr ass baa bab bad bai bar bas bba bbb bbd bbi bbr bbs bda bdb bdd bdi bdr bds bi- bia bib bid bii bir bis bra brb brd bri brr brs bsa bsb bsd bsi bsr bss daa dab dad dai dar das dba dbb dbd dbi dbr dbs dda ddb ddd ddi ddr dds di- dia dib did dii dir dis dra drb drd dri drr drs dsa dsb dsd dsi dsr dss i-d ia- iaa iab iad iai iar ias iba ibb ibd ibi ibr ibs ida idb idd idi idr ids iia iib iid iii iir iis ir- ira irb ird iri irr irs is- isa isb isd isi isr iss ra- raa rab rad rai rar ras rba rbb rbd rbi rbr rbs rda rdb rdd rdi rdr rds ria rib rid rii rir ris rra rrb rrd rri rrr rrs rsa rsb rsd rsi rsr rss saa sab sad sai sar sas sba sbb sbd sbi sbr sbs sda sdb sdd sdi sdr sds sia sib sid sii sir sis sr- sra srb srd sri srr srs ss- ssa ssb ssd ssi ssr sss