b-u bbb bbc bbe bbk bbu bcb bcc bce bck bcu be- beb bec bee bek beu bkb bkc bke bkk bub buc bue buk buu c-- cbb cbc cbe cbk cbu ccb ccc cce cck ccu ce- ceb cec cee cek ceu ckb ckc cub cuc cue cuk cuu ebb ebc ebe ebk ebu ec- ecb ecc ece eck ecu eeb eec eee eek ekb ekc eke eku eu- eub euc eue kbb kbc kbe kbk kbu kcb kcc kce kck kcu ke- keb kec kee kek kkb kkc kke kkk kku kub kuc kue kuk kuu ubb ubc ube ubk ubu ucb ucc uce uck ucu ueb uec uee ukb ukc uke ukk uku uuc uue uuu