-ic a-a a-b a-c a-i a-t aaa aab aac aaf aai aao aar aat ab- aba abb abc abf abi abo abr abt ac- aca acb acc acf aci aco acr act af- afa afb afc aff afi afo afr aft ai- aia aib aic aif aii aio air ait aoa aob aoc aof aoi aoo aor aot ar- ara arb arc arf ari aro arr art at- ata atb atc atf ati ato atr att baa bab bac baf bai bao bar bat bba bbb bbc bbf bbi bbo bbr bbt bca bcb bcc bcf bci bco bcr bct bfa bfb bfc bff bfi bfo bfr bft bi- bia bib bic bif bii bio bir bit boa bob boc bof boi boo bor bot bra brb brf bri bro brr brt bta btb btc btf bti bto btr btt c-- caa cab cac caf cai cao car cat cba cbb cbc cbf cbi cbo cbr cbt cca ccb ccc ccf cci cco ccr cct cfa cfb cfc cff cfi cfo cfr cft ci- cia cib cic cif cii cio cir cit co- coa cob coc cof coi coo cor cot cra crb crc crf cri cro crr crt cta ctb ctc ctf cti cto ctr ctt faa fab fac faf fai fao far fat fba fbb fbc fbf fbi fbo fbr fbt fca fcb fcc fcf fci fco fcr fct ffa ffc fff ffi ffo ffr fft fia fib fic fif fii fir fit foa fob foc fof foi foo for fot fra frb frc frf fri fro frr frt fta ftb ftc ftf fti fto ftr ftt i-f ia- iaa iab iac iaf iai iao iar iat iba ibb ibc ibf ibi ibo ibr ibt ica icb icc icf ici ico icr ict ifa ifb ifc iff ifi ifo ifr ift iia iib iic iif iii iio iir iit io- ioa iob ioc iof ioi ioo ior iot ir- ira irb irc irf iri iro irr irt ita itb itc itf iti ito itt o-i oaa oab oac oaf oai oao oar oat ob- oba obb obc obf obi obo obr obt oc- oca ocb occ ocf oci oco ocr oct of- ofa ofb ofc off ofi ofo ofr oft oia oib oic oif oii oio oir oit oo- ooa oob ooc oof ooi ooo oor oot or- ora orb orc orf ori oro orr ort ot- ota otb otc otf oti oto otr ott ra- raa rab rac raf rai rao rar rat rba rbb rbc rbf rbi rbo rbr rbt rca rcb rcc rcf rci rco rcr rct rfa rfb rfc rff rfi rfo rfr rft ria rib ric rif rii rio rir rit roa rob roc rof roi roo ror rot rra rrb rrc rrf rri rrr rrt rta rtb rtc rtf rti rto rtr rtt taa tab tac taf tai tao tar tat tba tbb tbc tbf tbi tbo tbr tbt tca tcb tcc tcf tci tco tcr tct tfa tfb tfc tff tfi tfo tfr tft tia tib tic tif tii tio tir tit to- toa tob toc tof toi too tor tot tra trb trc trf tri tro trr trt tta ttb ttc ttf tti tto ttr ttt