user: Question: What is the sum of Tujia population with the Zhangjiajie prefecture in Sangzhi county?
Columns: ['Province', 'Prefecture', 'County', 'Tujia Population', "% of China's Tujia Population"]
Types: ['text', 'text', 'text', 'real', 'text']
Sample row: ['Chongqing', 'Same', 'Youyang', 462444.0, '5.76%']
SQL:

assistant: SELECT SUM("Tujia Population") FROM "Table" WHERE "Prefecture" = 'Zhangjiajie' AND "County" = 'Sangzhi';