user: Question: What is the Pinyin for the item that has a density of 77?
Columns: ['Name', 'Hanzi', 'Hanyu Pinyin', 'Population (2010-11-01)', 'Area (km²)', 'Density (/km²)']
Types: ['text', 'text', 'text', 'text', 'text', 'text']
Sample row: ['Name', 'Hanzi', 'Hanyu Pinyin', 'Population (2010-11-01)', 'Area (km²)', 'Density (/km²)']
SQL:

assistant: SELECT "Hanyu Pinyin" FROM "Table" WHERE "Density (/km²)" = '77';