bbb bbc bbd bbe bbf bcb bcc bcd bce bcf bdb bdc bdd bde bdf be- beb bec bed bee bef bfb bfc bfd bfe bff c-- cbb cbc cbd cbe cbf ccb ccc ccd cce ccf cdb cdc cdd cde cdf ce- ceb cec ced cee cef cfb cfc cfd cfe cff dbb dbc dbd dbe dbf dcb dcc dcd dce dcf ddb ddc ddd dde ddf de- deb dec ded dee def dfb dfc dfd dfe dff ebb ebc ebd ebe ebf ec- ecb ecc ecd ece ecf ed- edb edc edd ede edf eeb eec eed eee eef ef- efb efc efd efe eff fbb fbc fbd fbe fbf fcb fcc fcd fce fcf fdb fdc fdd fde fdf feb fec fed fee fef ffc ffd ffe fff