a-a aaa aan aar aav aax an- ana ann anr anv anx ar- ara arn arr arv arx av- ava avn avr avx ax- axa axn axr axv axx naa nan nar nav nax nna nnn nnv nra nrn nrr nrv nrx nva nvn nvv nxv ra- raa ran rar rav rax rna rnn rnr rnv rra rrn rrr rva rvn rvr rvv rxr v-a vaa van var vav vax vn- vna vnr vnv vra vrn vrr vva vvr vvv vxa vxr vxv xaa xan xar xav xna xrx xxv xxx