ach Kakao ach_so
ach Kakao ach_so
on n on
ach kakao ach so .
 a x WORD_BOUNDARY k a k a oː WORD_BOUNDARY  a x WORD_BOUNDARY z oː WORD_BOUNDARY
a c h WORD_BOUNDARY k a k a o WORD_BOUNDARY a c h WORD_BOUNDARY s o WORD_BOUNDARY