iii iin iip iir iis in- ini inn inp inr ins ipi ipn ipp ipr ips ir- iri irn irp irr irs is- isi isn isp isr iss n-i nii nin nip nir nis nni nnn nnp nns npi npn npp npr nps nri nrn nrp nrr nrs nsi nsn nsp nsr nss p-p pii pin pip pir pis pn- pni pnn pnp pnr pns ppi ppn ppp ppr pps pri prn prp prr prs ps- psi psn psp psr pss rii rin rip rir ris rni rnn rnp rnr rns rpi rpn rpp rpr rps rri rrn rrp rrr rrs rsi rsn rsp rsr rss sii sin sip sir sis sni snn snp snr sns spi spn spp spr sps sr- sri srn srp srr srs ss- ssi ssn ssp ssr sss