Definition: In this task, you are given a sentence. You must judge whether a single noun or verb has been replaced with another word with the same part of speech. The inversion would result in the sentence sounding unnatural, So unnatural sentences will be considered changed. Label the instances as "Original" or "Changed" based on your judgment.
Input: There was a flaw in their logic , of course , but by the time they found this out it was always too late .
