a-a a-t aaa aaf aag aar aat af- afa aff afg afr aft ag- aga agf agg agr agt ar- ara arf arg arr art at- ata atf atg atr att faa faf fag far fat ffa fff ffg ffr fft fga fgf fgg fgr fgt fra frf frg frr frt fta ftf ftg ftr ftt gaa gaf gag gar gat gfa gff gfr gft gga ggg ggr ggt gra grf grg grr grt gta gtf gtg gtr gtt ra- raa raf rag rar rat rfa rff rfg rfr rft rga rgf rgg rgr rgt rra rrf rrg rrr rrt rta rtf rtg rtr rtt taa taf tag tar tat tfa tff tfg tfr tft tga tgf tgg tgr tgt tra trf trg trr trt tta ttf ttg ttr ttt