-er a-a a-b a-i aaa aab aad aae aag aai aao aar ab- aba abb abd abe abg abi abo abr ad- ada adb add ade adg adi ado adr aea aeb aed aee aeg aei aeo aer ag- aga agb agd age agg agi ago agr ai- aia aib aid aie aig aii aio air aoa aob aod aoe aog aoi aoo aor ar- ara arb ard are arg ari aro arr baa bab bad bae bag bai bao bar bba bbb bbd bbe bbg bbi bbo bbr bda bdb bdd bde bdg bdi bdo bdr be- bea beb bed bee beg bei beo ber bga bgb bgd bge bgg bgi bgo bgr bi- bia bib bid bie big bii bio bir boa bob bod boe bog boi boo bor bra brb brd bre brg bri bro brr daa dab dad dae dag dai dao dar dba dbb dbd dbe dbg dbi dbo dbr dda ddb ddd dde ddg ddi ddo ddr de- dea deb ded dee deg dei deo der dga dgd dge dgg dgi dgr di- dia dib did die dig dii dio dir doa dob dod doe dog doi doo dor dra drb drd dre drg dri dro drr eaa eab ead eae eag eai eao ear eba ebb ebd ebe ebg ebi ebo ebr ed- eda edb edd ede edg edi edo edr eea eeb eed eee eeg eeo eer ega egb egd ege egg egi ego egr eia eib eid eie eig eii eio eir eo- eoa eob eod eoe eog eoi eoo eor era erb erd ere erg eri ero err g-d gaa gab gad gae gag gai gao gar gba gbd gbe gbg gbi gbo gbr gda gdb gdd gde gdi gdo gdr ge- gea geb ged gee geg gei geo ger gga ggb ggd ggg ggi ggo ggr gia gib gid gie gig gii gio gir goa gob god goe gog goi goo gor gra grb grd gre grg gri gro grr i-d ia- iaa iab iad iae iag iai iao iar iba ibb ibd ibe ibg ibi ibo ibr ida idb idd ide idg idi ido idr ie- iea ied iee ieg iei ier iga igb igd ige igg igi igo igr iia iib iid iie iii iio iir io- ioa iob iod ioe iog ioi ioo ior ir- ira irb ird ire irg iri iro irr o-i oaa oab oad oae oag oai oao oar ob- oba obb obd obe obg obi obo obr oda odb odd ode odg odi odo odr oea oeb oed oee oeg oei oeo oer oga ogd oge ogg ogi ogo oia oib oid oie oii oio oir oo- ooa oob ood oog ooi ooo oor or- ora orb ord ore org ori oro orr ra- raa rab rad rae rag rai rao rar rba rbb rbd rbe rbg rbi rbo rbr rda rdb rdd rde rdg rdi rdo rdr re- rea reb red ree reg rei reo rer rga rgb rgd rge rgg rgi rgo rgr ria rib rid rie rig rii rio rir roa rob rod roe rog roi roo ror rra rrb rrd rrg rri rrr