How much do the top 3 components add up to?
{"Net operating loss carryforwards": {"2019": 19269, "2018": 22013}, "Depreciation, amortization and impairments": {"2019": -11945, "2018": -11112}, "Research and development credits": {"2019": 19189, "2018": 17432}, "Stock-based compensation": {"2019": 2783, "2018": 2376}, "Other tax credits": {"2019": 1018, "2018": 2015}, "Inventory reserve": {"2019": 624, "2018": 292}, "Warranty reserve": {"2019": 313, "2018": 429}, "Payroll and employee benefit accruals": {"2019": 2220, "2018": 1941}, "Allowance for doubtful accounts": {"2019": 454, "2018": 354}, "Other accrued liabilities": {"2019": 6208, "2018": 8975}, "Convertible debt": {"2019": -10822, "2018": -194}, "Other, net": {"2019": 3281, "2018": 3904}, "Gross deferred tax assets": {"2019": 32592, "2018": 48425}, "Valuation allowance": {"2019": -10929, "2018": -16844}, "Net deferred tax assets": {"2019": 21663, "2018": 31581}, "Reported as: -- Deferred tax assets": {"2019": 22626, "2018": 31581}, "Reported as: -- Deferred tax liabilities": {"2019": -963, "2018": "-"}, "Reported as: -- Net deferred tax assets": {"2019": 21663, "2018": 31581}}
top_3_components = [df["Net operating loss carryforwards"]["2019"], df["Research and development credits"]["2019"], df["Other accrued liabilities"]["2019"]]
answer = sum(top_3_components)