a-a aaa aan aao aas aax an- ana ann ano ans anx aoa aon aoo aos aox as- asa asn aso ass asx ax- axa axn axo axs axx naa nan nao nas nax nna nnn nno nns no- noa non noo nos nox nsa nsn nso nss nsx oaa oan oao oas oax on- ona onn ono ons onx oo- ooa oon ooo oos oox os- osa osn oso oss osx ox- oxa oxn oxo oxx saa san sao sas sax sna snn sno sns soa son soo sos sox ss- ssa ssn sso sss ssx sxn sxs xaa xan xas xna xno xns xoa xon xoo xos xox xsa xss xxo xxx