Task: Information Extraction
Input (English): Sentence1: Alex's son begged him to go hiking with a group of Alex's friends. Sentence2: Alex was concerned as his son was only 3. Sentence3: But Alex's friends promised to look after him. Sentence4: On the trail, the friends got too caught up in their conversation. Sentence5: Alex's son vanished and no one knew how.
Output (English): Friends, Son, Alex