a-a aaa aae aaf aak aap aea aee aef aek aep af- afa afe aff afk afp aka ake akk akp ap- apa ape apf apk app eaa eae eaf eak eap eea eee eef eek eep ef- efa efe eff efp eka eke ekf ekp ep- epa epe epf epp faa fae faf fak fap fea fee fef fek fep ffa ffe fff ffk ffp fka fkf fkk fkp fpa fpe fpk fpp ka- kaa kae kaf kak kap ke- kea kee kef kek kep kfa kff kke kkk kkp kpa kpe kpf kpk kpp p-p paa pae paf pak pap pea pee pef pek pep pfa pfe pff pfk pfp pka pke pkf pkp ppa ppe ppf ppk ppp