aku aku aku aku aku aku
aku aku aku aku aku aku .
a k u WORD_BOUNDARY  a k u WORD_BOUNDARY  a k u WORD_BOUNDARY  a k u WORD_BOUNDARY  a k u WORD_BOUNDARY  a k u WORD_BOUNDARY
a k u WORD_BOUNDARY a k u WORD_BOUNDARY a k u WORD_BOUNDARY a k u WORD_BOUNDARY a k u WORD_BOUNDARY a k u WORD_BOUNDARY