-er a-a a-b a-c aaa aab aac aad aae aag aar aau ab- aba abb abc abd abe abg abr abu ac- aca acb acc acd ace acg acr acu ad- ada adb adc add ade adg adr adu aea aeb aec aed aee aeg aer aeu ag- aga agb agc agd age agg agr agu ar- ara arb arc ard are arg arr aru au- aua aub auc aud aue aug aur b-u baa bab bac bad bae bag bar bau bba bbb bbc bbd bbe bbg bbr bbu bca bcb bcc bcd bce bcg bcr bcu bda bdb bdc bdd bde bdg bdr bdu be- bea beb bec bed bee beg ber beu bga bgb bgc bgd bge bgg bgr bgu bra brb brd bre brg brr bru bua bub buc bud bue bug bur buu c-- caa cab cac cad cae cag car cau cba cbb cbc cbd cbe cbg cbr cbu cca ccb ccc ccd cce ccg ccr ccu cda cdb cdc cdd cde cdg cdr cdu ce- cea ceb cec ced cee ceg cer ceu cga cgb cgc cgd cge cgg cgr cgu cra crb crc crd cre crg crr cru cua cub cuc cud cue cug cur cuu daa dab dac dad dae dag dar dau dba dbb dbc dbd dbe dbg dbr dbu dca dcb dcc dcd dce dcg dcr dcu dda ddb ddc ddd dde ddg ddr ddu de- dea deb dec ded dee deg der deu dga dgc dgd dge dgg dgr dgu dra drb drc drd dre drg drr dru dua dub duc dud due dug dur eaa eab eac ead eae eag ear eau eba ebb ebc ebd ebe ebg ebr ebu ec- eca ecb ecc ecd ece ecg ecr ecu ed- eda edb edc edd ede edg edr edu eea eeb eec eed eee eeg eer ega egb egc egd ege egg egr egu era erb erc erd ere erg err eru eu- eua eub euc eud eue eug eur g-d gaa gab gac gad gae gag gar gau gba gbc gbd gbe gbg gbr gbu gca gcb gcc gcd gce gcg gcr gcu gda gdb gdc gdd gde gdr gdu ge- gea geb gec ged gee geg ger geu gga ggb ggc ggd ggg ggr ggu gra grb grc grd gre grg grr gru gu- gua gub guc gud gue gug gur guu ra- raa rab rac rad rae rag rar rau rba rbb rbc rbd rbe rbg rbr rbu rca rcb rcc rcd rce rcg rcr rcu rda rdb rdc rdd rde rdg rdr rdu re- rea reb rec red ree reg rer reu rga rgb rgc rgd rge rgg rgr rra rrb rrc rrd rrg rrr rru rua rub ruc rud rue rug rur ruu ua- uaa uab uac uad uae uag uar uau uba ubb ubc ube ubg ubr ubu uca ucb ucc ucd uce ucg ucr ucu uda udb udc udd ude udg udr udu uea ueb uec ued uee ueg uer uga ugb ugc uge ugg ugr ugu ur- ura urb urc urd ure urg urr uru uua uuc uue uug uur uuu