a-a aaa aan aao aap aar an- ana ann ano anp anr aoa aon aoo aop aor ap- apa apn apo app apr ar- ara arn aro arp arr naa nan nao nap nar nna nnn nno nnp no- noa non noo nop nor npa npn npo npp npr nra nrn nro nrp nrr oaa oan oao oap oar on- ona onn ono onp onr oo- ooa oon ooo oop oor op- opa opn opo opp opr or- ora orn oro orp orr p-p paa pan pao pap par pn- pna pnn pno pnp pnr poa pon poo pop por ppa ppn ppo ppp ppr pra prn pro prp prr ra- raa ran rao rap rar rna rnn rno rnp rnr roa ron roo rop ror rpa rpn rpo rpp rpr rra rrn rrp rrr