-er -ic bbb bbc bbe bbf bbi bbo bbr bbx bcb bcc bce bcf bci bco bcr bcx be- beb bec bee bef bei beo ber bex bfb bfc bfe bff bfi bfo bfr bfx bi- bib bic bie bif bii bio bir bix bob boc boe bof boi boo bor box brb bre brf bri bro brr brx bxb bxi bxo bxx c-- cbb cbc cbe cbf cbi cbo cbr cbx ccb ccc cce ccf cci cco ccr ccx ce- ceb cec cee cef cei ceo cer cex cfb cfc cfe cff cfi cfo cfr cfx ci- cib cic cie cif cii cio cir cix co- cob coc coe cof coi coo cor cox crb crc cre crf cri cro crr crx cxc cxf cxi cxo cxr cxx ebb ebc ebe ebf ebi ebo ebr ebx ec- ecb ecc ece ecf eci eco ecr ecx eeb eec eee eef eeo eer eex ef- efb efc efe eff efi efo efr efx eib eic eie eif eii eio eir eix eo- eob eoc eoe eof eoi eoo eor erb erc ere erf eri ero err ex- exc exe exi exo exr exx fbb fbc fbe fbf fbi fbo fbr fbx fcb fcc fce fcf fci fco fcr fcx feb fec fee fef fei feo fer fex ffc ffe fff ffi ffo ffr ffx fib fic fie fif fii fir fix fob foc foe fof foi foo for fox frb frc fre frf fri fro frr fxe fxi fxr fxx i-f ibb ibc ibe ibf ibi ibo ibr ibx icb icc ice icf ici ico icr ie- iec iee ief iei ier iex ifb ifc ife iff ifi ifo ifr ifx iib iic iie iif iii iio iir iix io- iob ioc ioe iof ioi ioo ior ir- irb irc ire irf iri iro irr irx ixc ixe ixi o-i ob- obb obc obe obf obi obo obr obx oc- ocb occ ocf oci oco ocr ocx oeb oec oee oef oei oeo oer oex of- ofb ofc ofe off ofi ofo ofr ofx oib oic oie oif oii oio oir oo- oob ooc oof ooi ooo oor oox or- orb orc ore orf ori oro orr orx ox- oxb oxc oxf oxi oxo oxx rbb rbc rbe rbf rbi rbo rbr rbx rcb rcc rce rcf rci rco rcr rcx re- reb rec ree ref rei reo rer rex rfb rfc rfe rff rfi rfo rfr rib ric rie rif rii rio rir rix rob roc roe rof roi roo ror rox rrb rrc rrf rri rrr rxr xbc xbe xbr xbx xcb xcf xci xcr xcx xee xer xex xfe xfx xic xie xii xio xix xoc xof xoi xoo xor xox xrc xrf xrx xxi xxo xxx