On June 7, 2019, the U.S. Court of Appeals for the Ninth Circuit in Altera Corp. v. Commissioner upheld U.S. Treasury Department regulations requiring that related parties in a cost-sharing arrangement share expenses related to stock-based compensation in proportion to the economic activity of the parties. The ruling reversed the prior decision of the U.S. Tax Court. On November 12, 2019, the Ninth Circuit Court of Appeals denied the plaintiff’s request for an en banc rehearing. Based on the appellate court’s ruling, the Company recorded a cumulative income tax expense of $5.3 million in the fourth quarter of 2019. The plaintiff filed a petition for a writ of certiorari in the U.S. Supreme Court on February 10, 2020, and the Company will continue to monitor developments in this matter. The tax effects of temporary differences that give rise to significant portions of the deferred tax assets were as follows (in thousands): The Company accounts for deferred taxes under ASC Topic 740, “Income Taxes” (“ASC 740”) which involves weighing positive and negative evidence concerning the realizability of the Company’s deferred tax assets in each jurisdiction. The Company evaluated its ability to realize the benefit of its net deferred tax assets and weighed all available positive and negative evidence both objective and subjective in nature. In determining the need for a valuation allowance, the weight given to positive and negative evidence is commensurate with the extent to which the evidence may be objectively verified. Consideration was given to negative evidence such as: the duration and severity of losses in prior years, high seasonal revenue concentrations, increasing competitive pressures, and a challenging retail environment. Realization of the Company’s net deferred tax assets is dependent upon its generation of sufficient taxable income in future years in appropriate tax jurisdictions to obtain benefit from the reversal of temporary differences, net operating loss carryforwards and tax credit carryforwards. The amount of net deferred tax assets considered realizable is subject to adjustment in future periods if estimates of future taxable income change. The Company recorded a valuation allowance to reduce its deferred tax assets to the net amount that the Company believes is more likely than not to be realized. As of December 31, 2019, the Company has a valuation allowance of $191.7 million against its U.S. deferred tax assets and a valuation allowance of $52.9 million against certain of its foreign deferred tax assets that the Company is not expected to realize. The Company will continue to assess the realizability of its deferred tax assets in each of the applicable jurisdictions going forward. As of December 31, 2019, the Company has U.S. federal net operating loss carryforwards of $316.2 million which expire beginning after 2032, California net operating loss carryforwards of $57.3 million which expire beginning after 2032, and other states net operating loss carryforwards of $52.1 million which expire beginning after 2023. As of December 31, 2019, the Company has U.S. federal research tax credit carryforwards of approximately $22.6 million, which if not utilized, begin to expire after 2031, California research tax credit carryforwards of approximately $45.0 million, which do not expire, Massachusetts research tax credit carryforwards of approximately $2.9 million, which if not utilized, begin to expire after 2028,

December 31,

2019	2018

Deferred tax assets:

Net operating losses and credits	$113,475	$61,494

Fixed assets and intangible assets	61,932	55,476

Accruals and reserves	75,133	53,818

Stock-based compensation	8,615	9,494

Inventory	429	911

Other	5,287	4,806

Total deferred tax assets	264,871	185,999

Less: valuation allowance	(244,581)	(181,122)

Deferred tax assets, net of valuation allowance	20,290	4,877

Deferred tax liabilities:

Accruals and reserves	(15,525)	—

Other	(914)	(560)

Total deferred tax liabilities	(16,439)	(560)

Net deferred tax assets	$3,851	$4,317

Question: What is the average inventory for 2018 and 2019?
Answer: 670