aaaa aaab aaac aaaf aaap aaba aabb aabc aabp aaca aacb aacc aacf aacp aafa aafb aafc aaff aapa aapc abaa abab abac abaf abap abb- abba abbb abca abcb abcc abcf abcp abff abpa abpc abpp acaa acab acac acap acba acca accc accf accp acfc acpa afaa afap afca afcb afcc affa affc afpa afpc apac apap apba apca apcb apcc apfa apfc appa appc baaa baaf baba babb bac- baca bacc bafc baff bapa bapc bapp bbbb bbfc bcaa bcap bcbc bcbp bcca bccc bcfc bcpp bfca bfpp bpcp bpfc caaa caab caac caaf caap caba cabf cac- caca cacc cafa cafb cafc caff capa capb capc capp cbac cbbc cbca cbcc cbcp cbfb cbfc cbpc cbpp ccaa ccab ccac ccaf ccap ccba ccbc ccca cccb cccc cccf cccp ccfa ccfc ccff ccpa ccpp cfaa cfab cfac cfbc cfca cfcb cfcf cffb cfpa cpaa cpac cpaf cpap cpbc cpca cpff cppa faaa faac faap faba faca facc facp fafa fafc faff fapa fapp fcab fcap fcba fcca fccf fccp fcpa ffcc ffff fp-c fpaa fpcc paap paba paca pafa pafc paff papa papb papp pbac pbcc pbpa pcaa pcaf pcap pcba pcbc pcca pccc pcfc pcpb pcpp pfaa pfcb pfff ppac ppap ppcc ppfa pppa pppp