As of the end of 2020, what was the total amount of Upstart Holdings' Total liabilities, convertible preferred stock and stockholders’ equity (deficit)? (answer in thousands of dollars, rounded to the nearest integer)

```reference [{"type":"table-json","id":22}] ``` The combined line item on Upstart Holdings’ balance sheet as of December 31 2020 was roughly $477,255 thousand. We obtained the FY-2020 balance-sheet data directly from the internal FMP database, which provided total liabilities, preferred stock, and total stockholders’ equity figures. Summing these values yielded the reported total liabilities plus convertible preferred stock and stockholders’ equity (deficit) .