iii iin iio iip iis in- ini inn ino inp ins io- ioi ion ioo iop ios ipi ipn ipo ipp ips is- isi isn iso isp iss n-i nii nin nio nip nis nni nnn nno nnp nns no- noi non noo nop nos npi npn npo npp nps nsi nsn nso nsp nss o-i oii oin oio oip ois on- oni onn ono onp ons oo- ooi oon ooo oop oos op- opi opn opo opp ops os- osi osn oso osp oss p-p pii pin pio pip pis pn- pni pnn pno pnp pns poi pon poo pop pos ppi ppn ppo ppp pps ps- psi psn pso psp pss sii sin sio sip sis sni snn sno snp sns soi son soo sop sos spi spn spo spp sps ss- ssi ssn sso ssp sss