fak+fak o fak+fak
fak fak o fak fak .
f a k WORD_BOUNDARY f a k WORD_BOUNDARY o WORD_BOUNDARY f a k WORD_BOUNDARY f a k WORD_BOUNDARY
f a k WORD_BOUNDARY f a k WORD_BOUNDARY o WORD_BOUNDARY f a k WORD_BOUNDARY f a k WORD_BOUNDARY