-er a-a a-b a-c aaa aab aac aad aae aar aas aau ab- aba abb abc abd abe abr abs abu ac- aca acb acc acd ace acr acs acu ad- ada adb adc add ade adr ads adu aea aeb aec aed aee aer aes aeu ar- ara arb arc ard are arr ars aru as- asa asb asc asd ase asr ass asu au- aua aub auc aud aue aur aus b-u baa bab bac bad bae bar bas bau bba bbb bbc bbd bbe bbr bbs bbu bca bcb bcc bcd bce bcr bcs bcu bda bdb bdc bdd bde bdr bds bdu be- bea beb bec bed bee ber bes beu bra brb brd bre brr brs bru bsa bsb bsc bsd bse bsr bss bsu bua bub buc bud bue bur bus buu c-- caa cab cac cad cae car cas cau cba cbb cbc cbd cbe cbr cbs cbu cca ccb ccc ccd cce ccr ccs ccu cda cdb cdc cdd cde cdr cds cdu ce- cea ceb cec ced cee cer ces ceu cra crb crc crd cre crr crs cru csa csb csc csd cse csr css csu cua cub cuc cud cue cur cus cuu daa dab dac dad dae dar das dau dba dbb dbc dbd dbe dbr dbs dbu dca dcb dcc dcd dce dcr dcs dcu dda ddb ddc ddd dde ddr dds ddu de- dea deb dec ded dee der des deu dra drb drc drd dre drr drs dru dsa dsb dsc dsd dse dsr dss dsu dua dub duc dud due dur dus eaa eab eac ead eae ear eas eau eba ebb ebc ebd ebe ebr ebs ebu ec- eca ecb ecc ecd ece ecr ecs ecu ed- eda edb edc edd ede edr eds edu eea eeb eec eed eee eer ees era erb erc erd ere err ers eru es- esa esb esc esd ese esr ess esu eu- eua eub euc eud eue eur eus ra- raa rab rac rad rae rar ras rau rba rbb rbc rbd rbe rbr rbs rbu rca rcb rcc rcd rce rcr rcs rcu rda rdb rdc rdd rde rdr rds rdu re- rea reb rec red ree rer res reu rra rrb rrc rrd rrr rrs rru rsa rsb rsc rsd rse rsr rss rsu rua rub ruc rud rue rur rus ruu saa sab sac sad sae sar sas sau sba sbb sbc sbd sbe sbr sbs sbu sca scb scc scd sce scr scs scu sda sdb sdc sdd sde sdr sds sdu se- sea seb sec sed see ser ses seu sr- sra srb src srd sre srr srs ss- ssa ssb ssc ssd sse ssr sss ssu sua sub suc sud sue sur sus suu ua- uaa uab uac uad uae uar uas uau uba ubb ubc ube ubr ubs ubu uca ucb ucc ucd uce ucr ucs ucu uda udb udc udd ude udr uds udu uea ueb uec ued uee uer ues ur- ura urb urc urd ure urr urs uru usa usb usc usd use usr uss usu uua uuc uue uur uus uuu