a-a a-t aaa aaf aao aar aat af- afa aff afo afr aft aoa aof aoo aor aot ar- ara arf aro arr art at- ata atf ato atr att faa faf fao far fat ffa fff ffo ffr fft foa fof foo for fot fra frf fro frr frt fta ftf fto ftr ftt oaa oaf oao oar oat of- ofa off ofo ofr oft oo- ooa oof ooo oor oot or- ora orf oro orr ort ot- ota otf oto otr ott ra- raa raf rao rar rat rfa rff rfo rfr rft roa rof roo ror rot rra rrf rrr rrt rta rtf rto rtr rtt taa taf tao tar tat tfa tff tfo tfr tft to- toa tof too tor tot tra trf tro trr trt tta ttf tto ttr ttt