In this task, you're given a pair of sentences, sentence 1 and sentence 2, that agree with each other. Your job is to alter sentence 2 so that the pair contradict each other. Generated sentences must be short, with less than 15 words. New information can be introduced. Avoid using pronouns to confuse the subject of the sentence.

Example Input: Sentence 1: A guy wearing a black shirt and a red hat riding his skateboard. Sentence 2: A guy is riding a skateboard.
Example Output: A guy is riding a scooter.

Example Input: Sentence 1: A man in a red uniform makes a jump in a dirt bike race. Sentence 2: The man is competing against other racers.
Example Output: The man is riding by himself.

Example Input: Sentence 1: A man laying on the floor as he works on an unfinished wooden chair with a tool on the ground. Sentence 2: The man is working on a chair.
Example Output:
The man is sitting on a bench.