Question: how many movies are in the aliens series
[{'answer': 'six', 'provenance': [{'wikipedia_id': '6245494', 'title': 'Alien (franchise)', 'start_paragraph_id': 29, 'start_character': 740, 'end_paragraph_id': 29, 'end_character': 743, 'bleu_score': 1.0, 'section': 'Section::::Films.:Short films.\n'}]}, {'provenance': [{'wikipedia_id': '6245494', 'title': 'Alien (franchise)', 'start_paragraph_id': 79, 'start_character': 0, 'end_paragraph_id': 79, 'end_character': 597, 'bleu_score': 0.9227440721091961, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 4956809197955275511}, 'section': 'Section::::Other media.:Novels.\n'}]}]