Question: which figure in the pan-african movement organized the first pan-african conference in 1900
[{'answer': 'Henry Sylvester Williams', 'provenance': [{'wikipedia_id': '37398011', 'title': 'First Pan-African Conference', 'start_paragraph_id': 1, 'start_character': 241, 'end_paragraph_id': 1, 'end_character': 265, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '37398011', 'title': 'First Pan-African Conference', 'start_paragraph_id': 1, 'start_character': 22, 'end_paragraph_id': 1, 'end_character': 967, 'bleu_score': 0.93508704463025, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 17615990590841958647}, 'section': 'Section::::Abstract.'}]}]