Question: who became the president of poland in 1990
[{'answer': 'Lech Wałęsa', 'provenance': [{'wikipedia_id': '1141664', 'title': '1990 Polish presidential election', 'start_paragraph_id': 2, 'start_character': 39, 'end_paragraph_id': 2, 'end_character': 50, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '1141664', 'title': '1990 Polish presidential election', 'start_paragraph_id': 2, 'start_character': 0, 'end_paragraph_id': 2, 'end_character': 253, 'bleu_score': 0.9529077664391161, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 1103654538904034873}, 'section': 'Section::::Abstract.'}]}]