-er a-a a-b a-c aaa aab aac aae aag aam aao aar ab- aba abb abc abe abg abm abo abr ac- aca acb acc ace acg acm aco acr aea aeb aec aee aeg aem aeo aer ag- aga agb agc age agg agm ago agr ama amb amc ame amg amm amo amr aoa aob aoc aoe aog aom aoo aor ar- ara arb arc are arg arm aro arr baa bab bac bae bag bam bao bar bba bbb bbc bbe bbg bbm bbo bbr bca bcb bcc bce bcg bcm bco bcr be- bea beb bec bee beg bem beo ber bga bgb bgc bge bgg bgm bgo bgr bma bmb bmc bme bmg bmm bmo bmr boa bob boc boe bog bom boo bor bra brb bre brg brm bro brr c-- caa cab cac cae cag cam cao car cba cbb cbc cbe cbg cbm cbo cbr cca ccb ccc cce ccg ccm cco ccr ce- cea ceb cec cee ceg cem ceo cer cga cgb cgc cge cgg cgm cgo cgr cma cmb cmc cme cmg cmm cmo cmr co- coa cob coc coe cog com coo cor cra crb crc cre crg crm cro crr eaa eab eac eae eag eam eao ear eba ebb ebc ebe ebg ebm ebo ebr ec- eca ecb ecc ece ecg ecm eco ecr eea eeb eec eee eeg eem eeo eer ega egb egc ege egg egm ego egr em- ema emb emc eme emg emm emo emr eo- eoa eob eoc eoe eog eom eoo eor era erb erc ere erg erm ero err gaa gab gac gae gag gam gao gar gba gbc gbe gbg gbm gbo gbr gca gcb gcc gce gcg gcm gco gcr ge- gea geb gec gee geg gem geo ger gga ggb ggc ggg ggm ggo ggr gma gmb gmc gme gmg gmm gmo gmr goa gob goc goe gog gom goo gor gra grb grc gre grg grm gro grr m-o m-r maa mab mac mae mag mam mao mar mba mbb mbc mbe mbg mbm mbo mbr mc- mca mcb mcc mce mcg mcm mco mcr mea meb mec mee meg mem meo mer mga mgb mgc mge mgm mgo mgr mma mmb mmc mme mmg mmm mmo mmr moa mob moc moe mog mom moo mor mra mrb mrc mre mrg mrm mro mrr oaa oab oac oae oag oam oao oar ob- oba obb obc obe obg obm obo obr oc- oca ocb occ ocg ocm oco ocr oea oeb oec oee oeg oem oeo oer oga ogc oge ogg ogo om- oma omb omc ome omg omm omo omr oo- ooa oob ooc oog oom ooo oor or- ora orb orc ore org orm oro orr ra- raa rab rac rae rag ram rao rar rba rbb rbc rbe rbg rbm rbo rbr rca rcb rcc rce rcg rcm rco rcr re- rea reb rec ree reg rem reo rer rga rgb rgc rge rgg rgo rgr rma rmb rmc rme rmg rmm rmo rmr roa rob roc roe rog rom roo ror rra rrb rrc rrg rrm rrr