-ic b-u bbb bbc bbd bbf bbi bbt bbu bcb bcc bcd bcf bci bct bcu bdb bdc bdd bdf bdi bdt bdu bfb bfc bfd bff bfi bft bfu bi- bib bic bid bif bii bit biu btb btc btd btf bti btt btu bub buc bud buf bui but buu c-- cbb cbc cbd cbf cbi cbt cbu ccb ccc ccd ccf cci cct ccu cdb cdc cdd cdf cdi cdt cdu cfb cfc cfd cff cfi cft cfu ci- cib cic cid cif cii cit ciu ctb ctc ctd ctf cti ctt ctu cub cuc cud cuf cui cut cuu dbb dbc dbd dbf dbi dbt dbu dcb dcc dcd dcf dci dct dcu ddb ddc ddd ddf ddi ddt ddu dfb dfc dfd dff dfi dft dfu di- dib dic did dif dii dit diu dtb dtc dtd dtf dti dtt dtu dub duc dud duf dui dut fbb fbc fbd fbf fbi fbt fbu fcb fcc fcd fcf fci fct fcu fdb fdc fdd fdf fdi fdt fdu ffc ffd fff ffi fft ffu fib fic fid fif fii fit fiu ftb ftc ftd ftf fti ftt ftu fub fud fuf fui fut fuu i-d i-f ibb ibc ibd ibf ibi ibt ibu icb icc icd icf ici ict icu idb idc idd idf idi idt idu ifb ifc ifd iff ifi ift ifu iib iic iid iif iii iit iiu itb itc itd itf iti itt itu iu- iub iuc iud iui iut tbb tbc tbd tbf tbi tbt tbu tcb tcc tcd tcf tci tct tcu tdb tdc tdd tdf tdi tdt tdu tfb tfc tfd tff tfi tft tfu tib tic tid tif tii tit tiu ttb ttc ttd ttf tti ttt ttu tub tuc tud tuf tui tut tuu ubb ubc ubf ubi ubt ubu ucb ucc ucd ucf uci uct ucu udb udc udd udf udi udt udu ufc ufd uff ufi uft ufu uib uic uid uif uii uit uiu utb utc utd utf uti utt utu uuc uut uuu