Task: Sentence Ordering
Input (English): Sentence1: Finally, she remembered the lullaby her mother had sung to her. Sentence2: She walked him around but still he did not sleep. Sentence3: She fed him but still he did not sleep. Sentence4: Once there was a mother who was desperate for her baby to sleep. Sentence5: The mother gently sung the lullaby to her baby.
Output (English): 42315