-al a-a a-b a-c aaa aab aac aag aal aar ab- aba abb abc abg abl abr ac- aca acb acc acg acl acr ag- aga agb agc agg agl agr al- ala alb alc alg all alr ar- ara arb arc arg arl arr baa bab bac bag bal bar bba bbb bbc bbg bbl bbr bca bcb bcc bcg bcl bcr bga bgb bgc bgg bgl bgr bla blb blc blg bll blr bra brb brg brl brr c-- caa cab cac cag cal car cba cbb cbc cbg cbl cbr cca ccb ccc ccg ccl ccr cga cgb cgc cgg cgl cgr cl- cla clb clc clg cll clr cra crb crc crg crl crr gaa gab gac gag gal gar gba gbc gbg gbl gbr gca gcb gcc gcg gcl gcr gga ggb ggc ggg ggr gla glb glc glg gll glr gra grb grc grg grl grr la- laa lab lac lag lal lar lba lbb lbc lbg lbl lbr lca lcb lcc lcg lcl lcr lga lgb lgc lgg lgl lgr lla llb llc llg lll llr lra lrb lrc lrg lrr ra- raa rab rac rag ral rar rba rbb rbc rbg rbl rbr rca rcb rcc rcg rcl rcr rga rgb rgc rgg rgr rla rlc rlg rll rlr rra rrb rrc rrg rrl rrr