a-a a-b a-c aaa aab aac aae aaf aah aan aao ab- aba abb abc abe abf abh abn abo ac- aca acb acc ace acf ach acn aco aea aeb aec aee aef aeh aen aeo af- afa afb afc afe aff afh afn afo aha ahb ahc ahe ahf ahh ahn aho an- ana anb anc ane anf anh ann ano aoa aob aoc aoe aof aoh aon aoo baa bab bac bae baf bah ban bao bba bbb bbc bbe bbf bbh bbn bbo bca bcb bcc bce bcf bch bcn bco be- bea beb bec bee bef beh ben beo bfa bfb bfc bfe bff bfh bfn bfo bha bhb bhc bhe bhf bhh bho bna bnb bnc bne bnf bnn bno boa bob boc boe bof boh bon boo c-- caa cab cac cae caf cah can cao cba cbb cbc cbe cbf cbh cbn cbo cca ccb ccc cce ccf cch ccn cco ce- cea ceb cec cee cef ceh cen ceo cfa cfb cfc cfe cff cfh cfn cfo ch- cha chb chc che chf chh chn cho cn- cna cnb cnc cne cnf cnh cnn cno co- coa cob coc coe cof coh con coo eaa eab eac eae eaf eah ean eao eba ebb ebc ebe ebf ebh ebn ebo ec- eca ecb ecc ece ecf ech ecn eco eea eeb eec eee eef een eeo ef- efa efb efc efe eff efh efo eha ehb ehc ehe ehf ehh ehn eho en- ena enb enc ene enf enh enn eno eo- eoa eob eoc eoe eof eoh eon eoo faa fab fac fae faf fah fan fao fba fbb fbc fbe fbf fbh fbn fbo fca fcb fcc fce fcf fcn fco fea feb fec fee fef feh fen feo ffa ffc ffe fff ffh ffn ffo fha fhb fhc fhe fhf fhh fhn fho fna fnb fnc fne fnf fnh fnn foa fob foc foe fof foh fon foo haa hab hac hae haf hah han hao hba hbb hbc hbe hbf hbh hbn hbo hca hcb hcc hce hcf hch hcn hco he- hea heb hec hee hef heh hen heo hfa hfb hfc hfe hff hfh hfn hfo hha hhb hhc hhe hhf hhh hhn hho hna hnb hnc hne hnf hnh hnn hno hoa hob hoc hoe hof hoh hon hoo naa nab nac nae naf nah nan nao nba nbb nbc nbe nbf nbn nbo nca ncb ncc nce ncf nch ncn nco ne- nea neb nec nee nef neh nen neo nfa nfb nfc nfe nff nfn nfo nha nhb nhc nhe nhf nhh nhn nna nnb nnc nne nnf nnh nnn nno no- noa nob noc noe nof noh non noo oaa oab oac oae oaf oah oan oao ob- oba obb obc obe obf obh obn obo oc- oca ocb occ ocf och ocn oco oea oeb oec oee oef oeh oen oeo of- ofa ofb ofc ofe off ofn ofo oha ohc ohe ohf ohh ohn oho on- ona onb onc one onf onh onn ono oo- ooa oob ooc oof ooh oon ooo