-er a-a a-b a-c aaa aab aac aae aag aar aav ab- aba abb abc abe abg abr abv ac- aca acb acc ace acg acr acv aea aeb aec aee aeg aer aev ag- aga agb agc age agg agr agv ar- ara arb arc are arg arr arv av- ava avb avc ave avg avr baa bab bac bae bag bar bav bba bbb bbc bbe bbg bbr bca bcb bcc bce bcg bcr bcv be- bea beb bec bee beg ber bev bga bgb bgc bge bgg bgr bgv bra brb bre brg brr brv bva bvb bvc bve bvg bvr bvv c-- caa cab cac cae cag car cav cba cbb cbc cbe cbg cbr cbv cca ccb ccc cce ccg ccr ccv ce- cea ceb cec cee ceg cer cev cga cgb cgc cge cgg cgr cgv cra crb crc cre crg crr crv cva cvb cvc cve cvg cvr cvv eaa eab eac eae eag ear eav eba ebb ebc ebe ebg ebr ebv ec- eca ecb ecc ece ecg ecr ecv eea eeb eec eee eeg eer eev ega egb egc ege egg egr era erb erc ere erg err erv eva evb evc eve evg evr evv gaa gab gac gae gag gar gav gba gbc gbe gbg gbr gbv gca gcb gcc gce gcg gcr ge- gea geb gec gee geg ger gev gga ggb ggc ggg ggr ggv gra grb grc gre grg grr grv gva gvb gvc gve gvg gvr ra- raa rab rac rae rag rar rav rba rbb rbc rbe rbg rbr rca rcb rcc rce rcg rcr rcv re- rea reb rec ree reg rer rev rga rgb rgc rge rgg rgr rgv rra rrb rrc rrg rrr rva rvb rvc rve rvg rvr rvv v-a v-e vaa vab vac vae vag var vav vba vbc vbg vbr vbv vca vcc vce vcr vea veb vec vee veg ver vga vgc vgg vgr vra vrb vrc vre vrg vrr vva vvb vvc vvg vvr vvv