a-a a-b a-i aaa aab aad aaf aai aar aas ab- aba abb abd abf abi abr abs ad- ada adb add adf adi adr ads af- afa afb afd aff afi afr afs ai- aia aib aid aif aii air ais ar- ara arb ard arf ari arr ars as- asa asb asd asf asi asr ass baa bab bad baf bai bar bas bba bbb bbd bbf bbi bbr bbs bda bdb bdd bdf bdi bdr bds bfa bfb bfd bff bfi bfr bfs bi- bia bib bid bif bii bir bis bra brb brd brf bri brr brs bsa bsb bsd bsf bsi bsr bss daa dab dad daf dai dar das dba dbb dbd dbf dbi dbr dbs dda ddb ddd ddf ddi ddr dds dfa dfb dfd dff dfi dfr dfs di- dia dib did dif dii dir dis dra drb drd dri drr drs dsa dsb dsd dsf dsi dsr dss faa fab fad faf fai far fas fba fbb fbd fbf fbi fbr fbs fda fdb fdd fdf fdi fdr fds ffa ffd fff ffi ffr ffs fia fib fid fif fii fir fis fra frb frd frf fri frr frs fsa fsb fsd fsf fsi fsr fss i-d i-f ia- iaa iab iad iaf iai iar ias iba ibb ibd ibf ibi ibr ibs ida idb idd idf idi idr ids ifa ifb ifd iff ifi ifr ifs iia iib iid iif iii iir iis ir- ira irb ird irf iri irr irs is- isa isb isd isf isi isr iss ra- raa rab rad raf rai rar ras rba rbb rbd rbf rbi rbr rbs rda rdb rdd rdf rdi rdr rds rfa rfb rfd rff rfi rfr rfs ria rib rid rif rii rir ris rra rrb rrd rrf rri rrr rrs rsa rsb rsd rsf rsi rsr rss saa sab sad saf sai sar sas sba sbb sbd sbf sbi sbr sbs sda sdb sdd sdf sdi sdr sds sfa sfb sfd sff sfi sfr sfs sia sib sid sif sii sir sis sr- sra srb srd srf sri srr srs ss- ssa ssb ssd ssf ssi ssr sss