Question: who won the pulitzer prize for letters fiction in 1961
[{'answer': 'Harper Lee', 'provenance': [{'wikipedia_id': '1020043', 'title': '1961 Pulitzer Prize', 'start_paragraph_id': 21, 'start_character': 39, 'end_paragraph_id': 21, 'end_character': 49, 'bleu_score': 1.0, 'section': 'Section::::Letters, Music and Drama Awards.\n'}]}]