a-a a-b a-t aaa aab aae aap aat ab- aba abb abe abp abt aea aeb aee aep aet ap- apa apb ape app apt at- ata atb ate atp att b-p baa bab bae bap bat bba bbb bbe bbp bbt be- bea beb bee bep bet bpa bpb bpe bpp bpt bta btb bte btp btt eaa eab eae eap eat eba ebb ebe ebp ebt eea eeb eee eep eet ep- epa epb epe epp ept eta etb ete etp ett p-p paa pab pae pap pat pba pbb pbe pbp pbt pea peb pee pep pet ppa ppb ppe ppp ppt pt- pta ptb pte ptp ptt taa tab tae tap tat tba tbb tbe tbp tbt te- tea teb tee tep tet tpa tpb tpe tpp tpt tta ttb tte ttp ttt