-er a-a a-b a-c aaa aab aac aae aag aah aao aar ab- aba abb abc abe abg abh abo abr ac- aca acb acc ace acg ach aco acr aea aeb aec aee aeg aeh aeo aer ag- aga agb agc age agg agh ago agr aha ahb ahc ahe ahg ahh aho ahr aoa aob aoc aoe aog aoh aoo aor ar- ara arb arc are arg arh aro arr baa bab bac bae bag bah bao bar bba bbb bbc bbe bbg bbh bbo bbr bca bcb bcc bce bcg bch bco bcr be- bea beb bec bee beg beh beo ber bga bgb bgc bge bgg bgh bgo bgr bha bhb bhc bhe bhg bhh bho bhr boa bob boc boe bog boh boo bor bra brb bre brg brh bro brr c-- caa cab cac cae cag cah cao car cba cbb cbc cbe cbg cbh cbo cbr cca ccb ccc cce ccg cch cco ccr ce- cea ceb cec cee ceg ceh ceo cer cga cgb cgc cge cgg cgh cgo cgr ch- cha chb chc che chg chh cho chr co- coa cob coc coe cog coh coo cor cra crb crc cre crg crh cro crr eaa eab eac eae eag eah eao ear eba ebb ebc ebe ebg ebh ebo ebr ec- eca ecb ecc ece ecg ech eco ecr eea eeb eec eee eeg eeo eer ega egb egc ege egg egh ego egr eha ehb ehc ehe ehg ehh eho ehr eo- eoa eob eoc eoe eog eoh eoo eor era erb erc ere erg erh ero err gaa gab gac gae gag gah gao gar gba gbc gbe gbg gbh gbo gbr gca gcb gcc gce gcg gch gco gcr ge- gea geb gec gee geg geh geo ger gga ggb ggc ggg ggh ggo ggr gha ghb ghc ghe ghg ghh gho ghr goa gob goc goe gog goh goo gor gra grb grc gre grg grh gro grr haa hab hac hae hag hah hao har hba hbb hbc hbe hbg hbh hbo hbr hca hcb hcc hce hcg hch hco hcr he- hea heb hec hee heg heh heo her hga hgb hgc hge hgg hgh hgo hgr hha hhb hhc hhe hhg hhh hho hhr hoa hob hoc hoe hog hoh hoo hor hr- hra hrb hrc hre hrg hrh hro hrr oaa oab oac oae oag oah oao oar ob- oba obb obc obe obg obh obo obr oc- oca ocb occ ocg och oco ocr oea oeb oec oee oeg oeh oeo oer oga ogc oge ogg ogh ogo oha ohc ohe ohg ohh oho ohr oo- ooa oob ooc oog ooh ooo oor or- ora orb orc ore org orh oro orr ra- raa rab rac rae rag rah rao rar rba rbb rbc rbe rbg rbh rbo rbr rca rcb rcc rce rcg rch rco rcr re- rea reb rec ree reg reh reo rer rga rgb rgc rge rgg rgh rgo rgr rh- rha rhb rhc rhe rhg rhh rho rhr roa rob roc roe rog roh roo ror rra rrb rrc rrg rrh rrr