a-a a-b a-c aaa aab aac aae aan aao aas aau ab- aba abb abc abe abn abo abs abu ac- aca acb acc ace acn aco acs acu aea aeb aec aee aen aeo aes aeu an- ana anb anc ane ann ano ans anu aoa aob aoc aoe aon aoo aos aou as- asa asb asc ase asn aso ass asu au- aua aub auc aue aun auo aus b-u baa bab bac bae ban bao bas bau bba bbb bbc bbe bbn bbo bbs bbu bca bcb bcc bce bcn bco bcs bcu be- bea beb bec bee ben beo bes beu bna bnb bnc bne bnn bno bns bnu boa bob boc boe bon boo bos bou bsa bsb bsc bse bsn bso bss bsu bua bub buc bue bun buo bus buu c-- caa cab cac cae can cao cas cau cba cbb cbc cbe cbn cbo cbs cbu cca ccb ccc cce ccn cco ccs ccu ce- cea ceb cec cee cen ceo ces ceu cn- cna cnb cnc cne cnn cno cns cnu co- coa cob coc coe con coo cos cou csa csb csc cse csn cso css csu cua cub cuc cue cun cuo cus cuu eaa eab eac eae ean eao eas eau eba ebb ebc ebe ebn ebo ebs ebu ec- eca ecb ecc ece ecn eco ecs ecu eea eeb eec eee een eeo ees en- ena enb enc ene enn eno ens enu eo- eoa eob eoc eoe eon eoo eos eou es- esa esb esc ese esn eso ess esu eu- eua eub euc eue eun eus naa nab nac nae nan nao nas nau nba nbb nbc nbe nbn nbo nbs nbu nca ncb ncc nce ncn nco ncs ncu ne- nea neb nec nee nen neo nes neu nna nnb nnc nne nnn nno nns nnu no- noa nob noc noe non noo nos nou nsa nsb nsc nse nsn nso nss nsu nua nub nuc nue nun nuo nus nuu oaa oab oac oae oan oao oas oau ob- oba obb obc obe obn obo obs obu oc- oca ocb occ ocn oco ocs ocu oea oeb oec oee oen oeo oes on- ona onb onc one onn ono ons onu oo- ooa oob ooc oon ooo oos os- osa osb osc ose osn oso oss osu ou- oua ouc oue oun ouo ous saa sab sac sae san sao sas sau sba sbb sbc sbe sbn sbo sbs sbu sca scb scc sce scn sco scs scu se- sea seb sec see sen seo ses seu sna snb snc sne snn sno sns snu soa sob soc soe son soo sos sou ss- ssa ssb ssc sse ssn sso sss ssu sua sub suc sue sun suo sus suu ua- uaa uab uac uae uan uao uas uau uba ubb ubc ube ubn ubo ubs ubu uca ucb ucc uce ucn uco ucs ucu uea ueb uec uee uen ues un- una unb unc une unn uno uns unu uoa uob uoc uoe uon uoo uos usa usb usc use usn uso uss usu uua uuc uue uun uus uuu