Question: who was the first president of bhartiya janta party when it was formally established
[{'answer': 'Syama Prasad Mookerjee'}, {'provenance': [{'wikipedia_id': '149330', 'title': 'Bharatiya Janata Party', 'start_paragraph_id': 2, 'start_character': 0, 'end_paragraph_id': 2, 'end_character': 821, 'bleu_score': 0.9415332868646721, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 11158327349788712314}, 'section': 'Section::::Abstract.'}]}]