-er a-a a-b a-t aaa aab aad aae aag aao aar aat ab- aba abb abd abe abg abo abr abt ad- ada adb add ade adg ado adr adt aea aeb aed aee aeg aeo aer aet ag- aga agb agd age agg ago agr agt aoa aob aod aoe aog aoo aor aot ar- ara arb ard are arg aro arr art at- ata atb atd ate atg ato atr att baa bab bad bae bag bao bar bat bba bbb bbd bbe bbg bbo bbr bbt bda bdb bdd bde bdg bdo bdr bdt be- bea beb bed bee beg beo ber bet bga bgb bgd bge bgg bgo bgr bgt boa bob bod boe bog boo bor bot bra brb brd bre brg bro brr brt bta btb btd bte btg bto btr btt daa dab dad dae dag dao dar dat dba dbb dbd dbe dbg dbo dbr dbt dda ddb ddd dde ddg ddo ddr ddt de- dea deb ded dee deg deo der det dga dgd dge dgg dgr dgt doa dob dod doe dog doo dor dot dra drb drd dre drg dro drr drt dta dtb dtd dte dtg dto dtr dtt eaa eab ead eae eag eao ear eat eba ebb ebd ebe ebg ebo ebr ebt ed- eda edb edd ede edg edo edr edt eea eeb eed eee eeg eeo eer eet ega egb egd ege egg ego egr egt eo- eoa eob eod eoe eog eoo eor eot era erb erd ere erg ero err ert eta etb etd ete etg eto etr ett g-d gaa gab gad gae gag gao gar gat gba gbd gbe gbg gbo gbr gbt gda gdb gdd gde gdo gdr gdt ge- gea geb ged gee geg geo ger get gga ggb ggd ggg ggo ggr ggt goa gob god goe gog goo gor got gra grb grd gre grg gro grr grt gta gtb gtd gte gtg gto gtr gtt oaa oab oad oae oag oao oar oat ob- oba obb obd obe obg obo obr obt oda odb odd ode odg odo odr odt oea oeb oed oee oeg oeo oer oet oga ogd oge ogg ogo ogt oo- ooa oob ood oog ooo oor oot or- ora orb ord ore org oro orr ort ot- ota otb otd ote otg oto otr ott ra- raa rab rad rae rag rao rar rat rba rbb rbd rbe rbg rbo rbr rbt rda rdb rdd rde rdg rdo rdr rdt re- rea reb red ree reg reo rer ret rga rgb rgd rge rgg rgo rgr rgt roa rob rod roe rog roo ror rot rra rrb rrd rrg rrr rrt rta rtb rtd rte rtg rto rtr rtt taa tab tad tae tag tao tar tat tba tbb tbd tbe tbg tbo tbr tbt tda tdb tdd tde tdg tdo tdr tdt te- tea teb ted tee teg teo ter tet tga tgb tge tgg tgo tgr tgt to- toa tob tod toe tog too tor tot tra trb trd tre trg tro trr trt tta ttb ttd tte ttg tto ttr ttt