bc-acb bd-adb bg-agb bk-akb bn-anb bt-atb cb-abc cd-adc ck-akc cn-anc cp-apc ct-atc db-abd dc-acd dg-agd dk-akd dp-apd dt-atd gb-abg gc-acg gd-adg gn-ang gp-apg gt-atg kb-abk kc-ack kd-adk kg-agk kn-ank kp-apk kt-atk nb-abn nc-acn nd-adn ng-agn nk-akn np-apn nt-atn pb-abp pc-acp pd-adp pk-akp pn-anp pt-atp tb-abt tc-act td-adt tk-akt tn-ant tp-apt