Opa sama Oma sama Papa
opa sama oma sama papa .
o p a WORD_BOUNDARY s a m a WORD_BOUNDARY  o m a WORD_BOUNDARY s a m a WORD_BOUNDARY p a p a WORD_BOUNDARY
o p a WORD_BOUNDARY s a m a WORD_BOUNDARY o m a WORD_BOUNDARY s a m a WORD_BOUNDARY p a p a WORD_BOUNDARY