bbb bbc bbe bbn bbt bcb bcc bce bcn bct be- beb bec bee ben bet bnb bnc bne bnn bnt btb btc bte btn btt c-- cbb cbc cbe cbn cbt ccb ccc cce ccn cct ce- ceb cec cee cen cet cn- cnb cnc cne cnn cnt ctb ctc cte ctn ctt ebb ebc ebe ebn ebt ec- ecb ecc ece ecn ect eeb eec eee een eet en- enb enc ene enn ent etb etc ete etn ett nbb nbc nbe nbn nbt ncb ncc nce ncn nct ne- neb nec nee nen net nnb nnc nne nnn nnt ntb ntc nte ntn ntt tbb tbc tbe tbn tbt tcb tcc tce tcn tct te- teb tec tee ten tet tnb tnc tne tnn tnt ttb ttc tte ttn ttt