-er -up a-a a-b a-c aaa aab aac aae aap aar aau ab- aba abb abc abe abp abr abu ac- aca acb acc ace acp acr acu aea aeb aec aee aep aer aeu ap- apa apb apc ape app apr apu ar- ara arb arc are arp arr aru au- aua aub auc aue aup aur b-p b-u baa bab bac bae bap bar bau bba bbb bbc bbe bbp bbr bbu bca bcb bcc bce bcp bcr bcu be- bea beb bec bee bep ber beu bpa bpb bpc bpe bpp bpr bpu bra brb bre brp brr bru bua bub buc bue bup bur buu c-- caa cab cac cae cap car cau cba cbb cbc cbe cbp cbr cbu cca ccb ccc cce ccp ccr ccu ce- cea ceb cec cee cep cer ceu cpa cpb cpc cpe cpp cpr cpu cra crb crc cre crp crr cru cua cub cuc cue cup cur cuu eaa eab eac eae eap ear eau eba ebb ebc ebe ebp ebr ebu ec- eca ecb ecc ece ecr ecu eea eeb eec eee eep eer ep- epa epb epc epe epp epr epu era erb erc ere erp err eru eu- eua eub euc eue eup eur p-p paa pab pac pae pap par pau pba pbb pbc pbe pbp pbr pbu pca pcb pcc pce pcp pcr pcu pea peb pec pee pep per peu ppa ppb ppc ppe ppp ppr ppu pra prb prc pre prp prr pru pua pub puc pue pup pur puu ra- raa rab rac rae rap rar rau rba rbb rbc rbe rbp rbr rbu rca rcb rcc rce rcp rcr rcu re- rea reb rec ree rep rer reu rpa rpb rpc rpe rpp rpr rpu rra rrb rrc rrp rrr rru rua rub ruc rue rup rur ruu ua- uaa uab uac uae uap uar uau uba ubb ubc ube ubp ubr ubu uca ucb ucc uce ucp ucr ucu uea ueb uec uee uep uer up- upa upb upc upe upp upr upu ur- ura urb urc ure urp urr uru uua uuc uue uur uuu