bbb bbc bbe bbf bbt bcb bcc bce bcf bct be- beb bec bee bef bet bfb bfc bfe bff bft btb btc bte btf btt c-- cbb cbc cbe cbf cbt ccb ccc cce ccf cct ce- ceb cec cee cef cet cfb cfc cfe cff cft ctb ctc cte ctf ctt ebb ebc ebe ebf ebt ec- ecb ecc ece ecf ect eeb eec eee eef eet ef- efb efc efe eff eft etb etc ete etf ett fbb fbc fbe fbf fbt fcb fcc fce fcf fct feb fec fee fef fet ffc ffe fff fft ftb ftc fte ftf ftt tbb tbc tbe tbf tbt tcb tcc tce tcf tct te- teb tec tee tef tet tfb tfc tfe tff tft ttb ttc tte ttf ttt