The 2015 income statement for Duffy’s Pest Control shows that depreciation expense was $208 million, EBIT was $526 million, and the tax rate was 35 percent. At the beginning of the year, the balance of gross fixed assets was $1,596 million and net operating working capital was $428 million. At the end of the year, gross fixed assets was $1,854 million. Duffy’s free cash flow for the year was $439 million.
Calculate the end-of-year balance for net operating working capital.