-er a-a a-b a-c aaa aab aac aae aag aar aas aau ab- aba abb abc abe abg abr abs abu ac- aca acb acc ace acg acr acs acu aea aeb aec aee aeg aer aes aeu ag- aga agb agc age agg agr ags agu ar- ara arb arc are arg arr ars aru as- asa asb asc ase asg asr ass asu au- aua aub auc aue aug aur aus b-u baa bab bac bae bag bar bas bau bba bbb bbc bbe bbg bbr bbs bbu bca bcb bcc bce bcg bcr bcs bcu be- bea beb bec bee beg ber bes beu bga bgb bgc bge bgg bgr bgs bgu bra brb bre brg brr brs bru bsa bsb bsc bse bsg bsr bss bsu bua bub buc bue bug bur bus buu c-- caa cab cac cae cag car cas cau cba cbb cbc cbe cbg cbr cbs cbu cca ccb ccc cce ccg ccr ccs ccu ce- cea ceb cec cee ceg cer ces ceu cga cgb cgc cge cgg cgr cgs cgu cra crb crc cre crg crr crs cru csa csb csc cse csg csr css csu cua cub cuc cue cug cur cus cuu eaa eab eac eae eag ear eas eau eba ebb ebc ebe ebg ebr ebs ebu ec- eca ecb ecc ece ecg ecr ecs ecu eea eeb eec eee eeg eer ees ega egb egc ege egg egr egs egu era erb erc ere erg err ers eru es- esa esb esc ese esg esr ess esu eu- eua eub euc eue eug eur eus gaa gab gac gae gag gar gas gau gba gbc gbe gbg gbr gbs gbu gca gcb gcc gce gcg gcr gcs gcu ge- gea geb gec gee geg ger ges geu gga ggb ggc ggg ggr ggs ggu gra grb grc gre grg grr grs gru gsa gsb gsc gse gsg gsr gss gsu gu- gua gub guc gue gug gur gus guu ra- raa rab rac rae rag rar ras rau rba rbb rbc rbe rbg rbr rbs rbu rca rcb rcc rce rcg rcr rcs rcu re- rea reb rec ree reg rer res reu rga rgb rgc rge rgg rgr rgs rra rrb rrc rrg rrr rrs rru rsa rsb rsc rse rsg rsr rss rsu rua rub ruc rue rug rur rus ruu saa sab sac sae sag sar sas sau sba sbb sbc sbe sbg sbr sbs sbu sca scb scc sce scg scr scs scu se- sea seb sec see seg ser ses seu sga sgb sgc sge sgg sgr sgs sgu sr- sra srb src sre srg srr srs ss- ssa ssb ssc sse ssg ssr sss ssu sua sub suc sue sug sur sus suu ua- uaa uab uac uae uag uar uas uau uba ubb ubc ube ubg ubr ubs ubu uca ucb ucc uce ucg ucr ucs ucu uea ueb uec uee ueg uer ues uga ugb ugc uge ugg ugr ugs ugu ur- ura urb urc ure urg urr urs uru usa usb usc use usg usr uss usu uua uuc uue uug uur uus uuu