a-a a-b a-c aaa aab aac aaj aak ab- aba abb abc abj abk ac- aca acb acc acj ack aja ajb ajc ajj ajk aka akb akc akj akk baa bab bac baj bak bba bbb bbc bbk bca bcb bcc bcj bck bja bjc bjj bjk bka bkb bkc bkk c-- c-j caa cab cac caj cak cba cbb cbc cbj cbk cca ccb ccc ccj cck cja cjb cjc cjk cka ckb ckc jaa jab jac jaj jak jba jbc jbj jbk jca jcb jcc jck jja jjb jjc jjj jjk jka jkb jkk ka- kaa kab kac kaj kak kba kbb kbc kbk kca kcb kcc kck kjb kjc kkb kkc kkk