a-a a-i aaa aaf aai aar aax af- afa aff afi afr afx ai- aia aif aii air aix ar- ara arf ari arr arx ax- axa axi axr axx faa faf fai far fax ffa fff ffi ffr ffx fia fif fii fir fix fra frf fri frr fxi fxr fxx i-f ia- iaa iaf iai iar ifa iff ifi ifr ifx iia iif iii iir iix ir- ira irf iri irr irx ixi ra- raa raf rai rar rax rfa rff rfi rfr ria rif rii rir rix rra rrf rri rrr rxr xaa xaf xar xfa xfx xia xii xix xrf xrx xxi xxx