Task: Sentence Ordering
Input (English): Sentence1: They decide to be lab partners in their class together. Sentence2: Rufus has just enrolled in a new school and he has no friends there. Sentence3: They realize that they are in the same Chemistry class. Sentence4: At first he feels apprehensive and worried he won't meet anyone. Sentence5: However, a nice guy named Ralph introduces himself to Rufus one day.
Output (English): 51423