Table:
|  |  | Years Ended December 31, |  |
| --- | --- | --- | --- |
|  | 2019 | 2018 | 2017 |
|  |  | (Dollars in millions) |  |
| Total segment adjusted EBITDA | $15,987 | 16,647 | 12,560 |
| Depreciation and amortization | (4,829) | (5,120) | (3,936) |
| Goodwill impairment | (6,506) | (2,726) | — |
| Other operating expenses | (7,216) | (8,045) | (6,504) |
| Share-based compensation | (162) | (186) | (111) |
| Operating (loss) income | (2,726) | 570 | 2,009 |
| Total other expense, net | (2,040) | (2,133) | (1,469) |
| (Loss) income before income taxes | (4,766) | (1,563) | 540 |
| Income tax expense (benefit) | 503 | 170 | (849) |
| Net (loss) income | $(5,269) | (1,733) | 1,389 |
Paragraphs:
The following table reconciles total segment adjusted EBITDA to net (loss) income for the years ended December 31, 2019, 2018 and 2017:
We do not have any single customer that provides more than 10% of our consolidated total operating revenue.
The assets we hold outside of the U.S. represent less than 10% of our total assets. Revenue from sources outside of the U.S. is responsible for less than 10% of our total operating revenue.
Question:
What is the sum of income tax expense (benefit) in 2018 and 2019?
Answer: 503+170 = 673