a-a a-b a-t aaa aab aae aag aan aao aat aax ab- aba abb abe abg abn abo abt abx aea aeb aee aeg aen aeo aet aex ag- aga agb age agg agn ago agt agx an- ana anb ane ang ann ano ant anx aoa aob aoe aog aon aoo aot aox at- ata atb ate atg atn ato att atx ax- axa axe axn axo axt axx baa bab bae bag ban bao bat bax bba bbb bbe bbg bbn bbo bbt bbx be- bea beb bee beg ben beo bet bex bga bgb bge bgg bgn bgo bgt bgx bna bnb bne bng bnn bno bnt bnx boa bob boe bog bon boo bot box bta btb bte btg btn bto btt btx bxb bxn bxo bxx eaa eab eae eag ean eao eat eax eba ebb ebe ebg ebn ebo ebt ebx eea eeb eee eeg een eeo eet eex ega egb ege egg egn ego egt egx en- ena enb ene eng enn eno ent eo- eoa eob eoe eog eon eoo eot eta etb ete etg etn eto ett etx ex- exa exe exo ext exx gaa gab gae gag gan gao gat gba gbe gbg gbn gbo gbt gbx ge- gea geb gee geg gen geo get gex gga ggb ggg ggn ggo ggt gna gnb gne gnn gno gnt goa gob goe gog gon goo got gox gta gtb gte gtg gtn gto gtt gtx gxa gxt naa nab nae nag nan nao nat nax nba nbb nbe nbg nbn nbo nbt nbx ne- nea neb nee neg nen neo net nex nga ngb nge ngg ngn ngo ngt nna nnb nne nng nnn nno nnt no- noa nob noe nog non noo not nox nta ntb nte ntg ntn nto ntt ntx nxt oaa oab oae oag oan oao oat oax ob- oba obb obe obg obn obo obt obx oea oeb oee oeg oen oeo oet oex oga oge ogg ogn ogo ogt ogx on- ona onb one ong onn ono ont onx oo- ooa oob oog oon ooo oot oox ot- ota otb ote otg otn oto ott ox- oxa oxb oxn oxo oxt oxx t-x taa tab tae tag tan tao tat tax tba tbb tbe tbg tbn tbo tbt te- tea teb tee teg ten teo tet tex tga tgb tge tgg tgn tgo tgt tna tnb tne tng tnn tno tnt tnx to- toa tob toe tog ton too tot tox tta ttb tte ttg ttn tto ttt ttx txe txn txt xaa xag xan xat xbe xbx xee xeg xen xet xex xge xna xno xoa xog xon xoo xot xox xtx xxo xxx