-er bbb bbc bbd bbe bbg bbr bcb bcc bcd bce bcg bcr bdb bdc bdd bde bdg bdr be- beb bec bed bee beg ber bgb bgc bgd bge bgg bgr brb brd bre brg brr c-- cbb cbc cbd cbe cbg cbr ccb ccc ccd cce ccg ccr cdb cdc cdd cde cdg cdr ce- ceb cec ced cee ceg cer cgb cgc cgd cge cgg cgr crb crc crd cre crg crr dbb dbc dbd dbe dbg dbr dcb dcc dcd dce dcg dcr ddb ddc ddd dde ddg ddr de- deb dec ded dee deg der dgc dgd dge dgg dgr drb drc drd dre drg drr ebb ebc ebd ebe ebg ebr ec- ecb ecc ecd ece ecg ecr ed- edb edc edd ede edg edr eeb eec eed eee eeg eer egb egc egd ege egg egr erb erc erd ere erg err g-d gbc gbd gbe gbg gbr gcb gcc gcd gce gcg gcr gdb gdc gdd gde gdr ge- geb gec ged gee geg ger ggb ggc ggd ggg ggr grb grc grd gre grg grr rbb rbc rbd rbe rbg rbr rcb rcc rcd rce rcg rcr rdb rdc rdd rde rdg rdr re- reb rec red ree reg rer rgb rgc rgd rge rgg rgr rrb rrc rrd rrg rrr