-er a-a a-b a-c aaa aab aac aae aag aah aak aar ab- aba abb abc abe abg abh abk abr ac- aca acb acc ace acg ach ack acr aea aeb aec aee aeg aeh aek aer ag- aga agb agc age agg agh agk agr aha ahb ahc ahe ahg ahh ahk ahr aka akb akc ake akg akh akk akr ar- ara arb arc are arg arh ark arr baa bab bac bae bag bah bak bar bba bbb bbc bbe bbg bbh bbk bbr bca bcb bcc bce bcg bch bck bcr be- bea beb bec bee beg beh bek ber bga bgb bgc bge bgg bgh bgk bgr bha bhb bhc bhe bhg bhh bhk bhr bka bkb bkc bke bkg bkk bkr bra brb bre brg brh brk brr c-- caa cab cac cae cag cah cak car cba cbb cbc cbe cbg cbh cbk cbr cca ccb ccc cce ccg cch cck ccr ce- cea ceb cec cee ceg ceh cek cer cga cgb cgc cge cgg cgh cgr ch- cha chb chc che chg chh chk chr cka ckb ckc ckh cra crb crc cre crg crh crk crr eaa eab eac eae eag eah eak ear eba ebb ebc ebe ebg ebh ebk ebr ec- eca ecb ecc ece ecg ech eck ecr eea eeb eec eee eeg eek eer ega egb egc ege egg egh egr eha ehb ehc ehe ehg ehh ehr eka ekb ekc eke ekg ekh ekr era erb erc ere erg erh erk err gaa gab gac gae gag gah gak gar gba gbc gbe gbg gbh gbk gbr gca gcb gcc gce gcg gch gck gcr ge- gea geb gec gee geg geh gek ger gga ggb ggc ggg ggh ggr gha ghb ghc ghe ghg ghh ghr gka gkb gkh gra grb grc gre grg grh grk grr haa hab hac hae hag hah hak har hba hbb hbc hbe hbg hbh hbk hbr hca hcb hcc hce hcg hch hck hcr he- hea heb hec hee heg heh hek her hga hgb hgc hge hgg hgh hgk hgr hha hhb hhc hhe hhg hhh hhk hhr hka hkb hkg hkh hkk hkr hr- hra hrb hrc hre hrg hrh hrk hrr ka- kaa kab kac kae kag kah kak kar kba kbb kbc kbe kbh kbk kbr kca kcb kcc kce kcg kch kck kcr ke- kea keb kec kee keg keh kek ker kga kgb kgc kgh kha khe khh khk khr kkb kkc kke kkh kkk kkr kra krc krg krk krr ra- raa rab rac rae rag rah rak rar rba rbb rbc rbe rbg rbh rbk rbr rca rcb rcc rce rcg rch rcr re- rea reb rec ree reg reh rek rer rga rgb rgc rge rgg rgh rgk rgr rh- rha rhb rhc rhe rhg rhh rhr rkb rkc rke rkg rkk rra rrb rrc rrg rrh rrk rrr