-al a-a a-b a-c aaa aab aac aae aal aau ab- aba abb abc abe abl abu ac- aca acb acc ace acl acu aea aeb aec aee ael aeu al- ala alb alc ale all alu au- aua aub auc aue aul b-u baa bab bac bae bal bau bba bbb bbc bbe bbl bbu bca bcb bcc bce bcl bcu be- bea beb bec bee bel beu bla blb blc ble bll blu bua bub buc bue bul buu c-- caa cab cac cae cal cau cba cbb cbc cbe cbl cbu cca ccb ccc cce ccl ccu ce- cea ceb cec cee cel ceu cl- cla clb clc cle cll clu cua cub cuc cue cul cuu eaa eab eac eae eal eau eba ebb ebc ebe ebl ebu ec- eca ecb ecc ece ecl ecu eea eeb eec eee eel ela elb elc ele ell elu eu- eua eub euc eue eul la- laa lab lac lae lal lau lba lbb lbc lbe lbl lbu lca lcb lcc lce lcl lcu lea leb lec lee lel leu lla llb llc lle lll llu lua lub luc lue lul luu ua- uaa uab uac uae ual uau uba ubb ubc ube ubl ubu uca ucb ucc uce ucl ucu uea ueb uec uee uel ula ulb ulc ule ull ulu uua uuc uue uuu