a-a a-b a-c aaa aab aac aae aau aax ab- aba abb abc abe abu abx ac- aca acb acc ace acu acx aea aeb aec aee aeu aex au- aua aub auc aue aux ax- axa axe axx b-u baa bab bac bae bau bax bba bbb bbc bbe bbu bbx bca bcb bcc bce bcu bcx be- bea beb bec bee beu bex bua bub buc bue buu bux bxb bxx c-- caa cab cac cae cau cax cba cbb cbc cbe cbu cbx cca ccb ccc cce ccu ccx ce- cea ceb cec cee ceu cex cua cub cuc cue cuu cxc cxx eaa eab eac eae eau eax eba ebb ebc ebe ebu ebx ec- eca ecb ecc ece ecu ecx eea eeb eec eee eex eu- eua eub euc eue eux ex- exa exc exe exu exx ua- uaa uab uac uae uau uba ubb ubc ube ubu ubx uca ucb ucc uce ucu uea ueb uec uee uua uuc uue uuu uxb uxc uxu xaa xac xau xbc xbe xbx xcb xcx xee xeu xex xue xxx