b-u bbb bbc bbd bbe bbk bbo bbt bbu bcb bcc bcd bce bck bco bct bcu bdb bdc bdd bde bdk bdo bdt bdu be- beb bec bed bee bek beo bet beu bkb bkc bke bkk bko bkt bob boc bod boe bok boo bot bou btb btc btd bte btk bto btt btu bub buc bud bue buk buo but buu c-- cbb cbc cbd cbe cbk cbo cbt cbu ccb ccc ccd cce cck cco cct ccu cdb cdc cdd cde cdk cdo cdt cdu ce- ceb cec ced cee cek ceo cet ceu ckb ckc ckd cko ckt co- cob coc cod coe cok coo cot cou ctb ctc ctd cte ctk cto ctt ctu cub cuc cud cue cuk cuo cut cuu dbb dbc dbd dbe dbk dbo dbt dbu dcb dcc dcd dce dck dco dct dcu ddb ddc ddd dde ddk ddo ddt ddu de- deb dec ded dee dek deo det deu dkb dkc dke dkk dko dkt dku dob doc dod doe dok doo dot dou dtb dtc dtd dte dtk dto dtt dtu dub duc dud due duk duo dut ebb ebc ebd ebe ebk ebo ebt ebu ec- ecb ecc ecd ece eck eco ect ecu ed- edb edc edd ede edk edo edt edu eeb eec eed eee eek eeo eet ekb ekc ekd eke eko ekt eku eo- eob eoc eod eoe eok eoo eot eou etb etc etd ete etk eto ett etu eu- eub euc eud eue eut k-t kbb kbc kbd kbe kbk kbo kbu kcb kcc kcd kce kck kct kcu kdb kdc kde kdk kdo kdt kdu ke- keb kec ked kee kek keo ket kkb kkc kke kkk kkt kku kob koc kod koe kok koo kot kou ktb ktc kte ktk kto ktt ktu kub kuc kud kue kuk kut kuu ob- obb obc obd obe obk obo obt obu oc- ocb occ ocd ock oco oct ocu odb odc odd ode odo odt odu oeb oec oed oee oeo oet okb okc okd oke okk oko oku oo- oob ooc ood ook ooo oot ot- otb otc otd ote otk oto ott otu ou- ouc oud oue ouk ouo out tbb tbc tbd tbe tbk tbo tbt tbu tcb tcc tcd tce tck tco tct tcu tdb tdc tdd tde tdk tdo tdt tdu te- teb tec ted tee tek teo tet teu tkb tkc tke tkk tko tkt to- tob toc tod toe tok too tot tou ttb ttc ttd tte ttk tto ttt ttu tub tuc tud tue tuk tuo tut tuu ubb ubc ube ubk ubo ubt ubu ucb ucc ucd uce uck uco uct ucu udb udc udd ude udk udo udt udu ueb uec ued uee uet ukb ukc uke ukk uku uob uoc uod uoe uok uoo uot utb utc utd ute utk uto utt utu uuc uue uut uuu