a mama mama mama mama
a mama mama mama mama .
a WORD_BOUNDARY m a m a WORD_BOUNDARY m a m a WORD_BOUNDARY m a m a WORD_BOUNDARY m a m a WORD_BOUNDARY
a WORD_BOUNDARY m a m a WORD_BOUNDARY m a m a WORD_BOUNDARY m a m a WORD_BOUNDARY m a m a WORD_BOUNDARY . WORD_BOUNDARY