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: They spent the rest of the day tracking the wolves ' movements and pushing them deeper into the mountains while staking the flags .
