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 rollerblader skates down a ramp with his arms in the air. Sentence 2: A rollerblader has his arms in the air.
Example Output: The rollerblader is a girl.

Example Input: Sentence 1: Person riding wave on stomach on a blue surfboard. Sentence 2: A person on a wave.
Example Output: Nobody on a wave.

Example Input: Sentence 1: Five men wearing black shorts are leaving the starting blocks in a track competition with few spectators. Sentence 2: Five men wearing black shorts walking.
Example Output:
Horses race around a track.