user: Question: What is the Hanyu Pinyin with an area of 400?
Columns: ['Name', 'Hanzi', 'Hanyu Pinyin', 'Uyghur ( UEY )', 'Uyghur Latin ( ULY )', 'Population (2010 Census)', 'Area (km²)', 'Density (/km²)']
Types: ['text', 'text', 'text', 'text', 'text', 'text', 'text', 'text']
Sample row: ['Name', 'Hanzi', 'Hanyu Pinyin', 'Uyghur ( UEY )', 'Uyghur Latin ( ULY )', 'Population (2010 Census)', 'Area (km²)', 'Density (/km²)']
SQL:

assistant: SELECT "Hanyu Pinyin" FROM "Table" WHERE "Area (km²)" = '400';