-ic b-p bbb bbc bbi bbo bbp bbt bcb bcc bci bco bcp bct bi- bib bic bii bio bip bit bob boc boi boo bop bot bpb bpc bpi bpo bpp bpt btb btc bti bto btp btt c-- cbb cbc cbi cbo cbp cbt ccb ccc cci cco ccp cct ci- cib cic cii cio cip cit co- cob coc coi coo cop cot cpb cpc cpi cpo cpp cpt ctb ctc cti cto ctp ctt ibb ibc ibi ibo ibp ibt icb icc ici ico icp ict iib iic iii iio iip iit io- iob ioc ioi ioo iop iot ipb ipc ipi ipo ipp ipt itb itc iti ito itp itt o-i ob- obb obc obi obo obp obt oc- ocb occ oci oco ocp oct oib oic oii oio oip oit oo- oob ooc ooi ooo oop oot op- opb opc opi opo opp opt ot- otb otc oti oto otp ott p-p pbb pbc pbi pbo pbp pbt pcb pcc pci pco pcp pct pib pic pii pio pip pit pob poc poi poo pop pot ppb ppc ppi ppo ppp ppt pt- ptb ptc pti pto ptp ptt tbb tbc tbi tbo tbp tbt tcb tcc tci tco tcp tct tib tic tii tio tip tit to- tob toc toi too top tot tpb tpc tpi tpo tpp tpt ttb ttc tti tto ttp ttt