Question: which european capital is served by the port of piraeus
[{'answer': 'Athens', 'provenance': [{'wikipedia_id': '98387', 'title': 'Piraeus', 'start_paragraph_id': 1, 'start_character': 117, 'end_paragraph_id': 1, 'end_character': 123, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '98387', 'title': 'Piraeus', 'start_paragraph_id': 3, 'start_character': 0, 'end_paragraph_id': 3, 'end_character': 814, 'bleu_score': 0.786669380980454, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 4857068732334836643}, 'section': 'Section::::Abstract.'}]}]