Question: which country has the most casualties in ww1
[{'answer': 'Russian Empire', 'provenance': [{'wikipedia_id': '33111', 'title': 'World War I casualties', 'start_paragraph_id': 16, 'start_character': 24, 'end_paragraph_id': 16, 'end_character': 38, 'bleu_score': 1.0, 'section': 'Section::::Casualties by post-war (1924) borders.\n'}]}]