Task: Sentence Ordering
Input (English): Sentence1: They were happy newlyweds, but wanted an addition to their family. Sentence2: Heather and Marcus were ready for the next step in their relationship. Sentence3: On a whim, they went to an animal shelter and fell in love with a cat. Sentence4: They adopted the cat. Sentence5: Although not quite ready for kids, they still felt lonely.
Output (English): 21453