a-a aaa aan aap aas aax an- ana ann anp ans anx ap- apa apn app aps apx as- asa asn asp ass asx ax- axa axn axp axs axx naa nan nap nas nax nna nnn nnp nns npa npn npp nps nsa nsn nsp nss nsx p-p paa pan pap pas pax pn- pna pnn pnp pns pnx ppa ppn ppp pps ppx ps- psa psn psp pss psx pxs saa san sap sas sax sna snn snp sns spa spn spp sps spx ss- ssa ssn ssp sss ssx sxn sxs xaa xan xap xas xna xns xpa xpn xpp xps xsa xsp xss xxp xxx