-er a-a a-b a-i aaa aab aad aae aai aap aar ab- aba abb abd abe abi abp abr ad- ada adb add ade adi adp adr aea aeb aed aee aei aep aer ai- aia aib aid aie aii aip air ap- apa apb apd ape api app apr ar- ara arb ard are ari arp arr b-p baa bab bad bae bai bap bar bba bbb bbd bbe bbi bbp bbr bda bdb bdd bde bdi bdp bdr be- bea beb bed bee bei bep ber bi- bia bib bid bie bii bip bir bpa bpb bpd bpe bpi bpp bpr bra brb brd bre bri brp brr daa dab dad dae dai dap dar dba dbb dbd dbe dbi dbp dbr dda ddb ddd dde ddi ddp ddr de- dea deb ded dee dei dep der di- dia dib did die dii dip dir dpa dpb dpd dpe dpi dpp dpr dra drb drd dre dri drp drr eaa eab ead eae eai eap ear eba ebb ebd ebe ebi ebp ebr ed- eda edb edd ede edi edp edr eea eeb eed eee eep eer eia eib eid eie eii eip eir ep- epa epb epd epe epi epp epr era erb erd ere eri erp err i-d ia- iaa iab iad iae iai iap iar iba ibb ibd ibe ibi ibp ibr ida idb idd ide idi idp idr ie- iea ied iee iei iep ier iia iib iid iie iii iip iir ipa ipb ipd ipe ipi ipp ipr ir- ira irb ird ire iri irp irr p-p paa pab pad pae pai pap par pba pbb pbd pbe pbi pbp pbr pda pdb pdd pde pdi pdp pdr pea peb ped pee pei pep per pia pib pid pie pii pip pir ppa ppb ppd ppe ppi ppp ppr pra prb prd pre pri prp prr ra- raa rab rad rae rai rap rar rba rbb rbd rbe rbi rbp rbr rda rdb rdd rde rdi rdp rdr re- rea reb red ree rei rep rer ria rib rid rie rii rip rir rpa rpb rpd rpe rpi rpp rpr rra rrb rrd rri rrp rrr