a-a a-b a-c aaa aab aac aad aae aak ab- aba abb abc abd abe abk ac- aca acb acc acd ace ack ad- ada adb adc add ade adk aea aeb aec aed aee aek aka akb akc akd ake akk baa bab bac bad bae bak bba bbb bbc bbd bbe bbk bca bcb bcc bcd bce bck bda bdb bdc bdd bde bdk be- bea beb bec bed bee bek bka bkb bkc bke bkk c-- caa cab cac cad cae cak cba cbb cbc cbd cbe cbk cca ccb ccc ccd cce cck cda cdb cdc cdd cde cdk ce- cea ceb cec ced cee cek cka ckb ckc ckd daa dab dac dad dae dak dba dbb dbc dbd dbe dbk dca dcb dcc dcd dce dck dda ddb ddc ddd dde ddk de- dea deb dec ded dee dek dka dkb dkc dke dkk eaa eab eac ead eae eak eba ebb ebc ebd ebe ebk ec- eca ecb ecc ecd ece eck ed- eda edb edc edd ede edk eea eeb eec eed eee eek eka ekb ekc ekd eke ka- kaa kab kac kad kae kak kba kbb kbc kbd kbe kbk kca kcb kcc kcd kce kck kda kdb kdc kde kdk ke- kea keb kec ked kee kek kkb kkc kke kkk