-er a-a a-b a-c aaa aab aac aae aag aam aar ab- aba abb abc abe abg abm abr ac- aca acb acc ace acg acm acr aea aeb aec aee aeg aem aer ag- aga agb agc age agg agm agr ama amb amc ame amg amm amr ar- ara arb arc are arg arm arr baa bab bac bae bag bam bar bba bbb bbc bbe bbg bbm bbr bca bcb bcc bce bcg bcm bcr be- bea beb bec bee beg bem ber bga bgb bgc bge bgg bgm bgr bma bmb bmc bme bmg bmm bmr bra brb bre brg brm brr c-- caa cab cac cae cag cam car cba cbb cbc cbe cbg cbm cbr cca ccb ccc cce ccg ccm ccr ce- cea ceb cec cee ceg cem cer cga cgb cgc cge cgg cgm cgr cma cmb cmc cme cmg cmm cmr cra crb crc cre crg crm crr eaa eab eac eae eag eam ear eba ebb ebc ebe ebg ebm ebr ec- eca ecb ecc ece ecg ecm ecr eea eeb eec eee eeg eem eer ega egb egc ege egg egm egr em- ema emb emc eme emg emm emr era erb erc ere erg erm err gaa gab gac gae gag gam gar gba gbc gbe gbg gbm gbr gca gcb gcc gce gcg gcm gcr ge- gea geb gec gee geg gem ger gga ggb ggc ggg ggm ggr gma gmb gmc gme gmg gmm gmr gra grb grc gre grg grm grr m-r maa mab mac mae mag mam mar mba mbb mbc mbe mbg mbm mbr mc- mca mcb mcc mce mcg mcm mcr mea meb mec mee meg mem mer mga mgb mgc mge mgm mgr mma mmb mmc mme mmg mmm mmr mra mrb mrc mre mrg mrm mrr ra- raa rab rac rae rag ram rar rba rbb rbc rbe rbg rbm rbr rca rcb rcc rce rcg rcm rcr re- rea reb rec ree reg rem rer rga rgb rgc rge rgg rgr rma rmb rmc rme rmg rmm rmr rra rrb rrc rrg rrm rrr