bbb bbc bbd bbe bbk bcb bcc bcd bce bck bdb bdc bdd bde bdk be- beb bec bed bee bek bkb bkc bke bkk c-- cbb cbc cbd cbe cbk ccb ccc ccd cce cck cdb cdc cdd cde cdk ce- ceb cec ced cee cek ckb ckc ckd dbb dbc dbd dbe dbk dcb dcc dcd dce dck ddb ddc ddd dde ddk de- deb dec ded dee dek dkb dkc dke dkk ebb ebc ebd ebe ebk ec- ecb ecc ecd ece eck ed- edb edc edd ede edk eeb eec eed eee eek ekb ekc ekd eke kbb kbc kbd kbe kbk kcb kcc kcd kce kck kdb kdc kde kdk ke- keb kec ked kee kek kkb kkc kke kkk