Question: who was the founder president of harijan sevak sangh
[{'answer': 'Mahatma Gandhi', 'provenance': [{'wikipedia_id': '42679804', 'title': 'Harijan Sevak Sangh', 'start_paragraph_id': 1, 'start_character': 60, 'end_paragraph_id': 1, 'end_character': 74, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '42679804', 'title': 'Harijan Sevak Sangh', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 288, 'bleu_score': 0.7558359165068551, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 4003420768275776566}, 'section': 'Section::::Abstract.'}]}]