Question: which is a higher title prince or duke
[{'answer': 'Prince', 'provenance': [{'wikipedia_id': '605748', 'title': 'Imperial, royal and noble ranks', 'start_paragraph_id': 8, 'start_character': 375, 'end_paragraph_id': 8, 'end_character': 381, 'bleu_score': 1.0, 'section': 'Section::::Ranks and title.:Sovereign.:Common titles for European and Near Eastern monarchs.\n'}]}]