Please read the following table in Markdown format and then answer the question according to the table. Table cells in one row are seperated by '|', and different rows are seperated by '
'.

Table:
|  | Year Ended December 31, | Year Ended December 31, | Year Ended December 31, |
| --- | --- | --- | --- |
|  | 2018 | 2017 | 2016 |
| Fleet restructuring expenses (1) | $422 | $232 | $177 |
| Merger integration expenses (2) | 268 | 273 | 514 |
| Severance expenses (3) | 58 | — | — |
| Litigation settlement (4) | 45 | — | — |
| Intangible asset impairment (5) | 26 | — | — |
| Labor contract expenses | 13 | 46 | — |
| Mark-to-market adjustments on bankruptcy obligations, net (6) | (76) | 27 | 25 |
| Employee 2017 Tax Act bonus expense (7) | — | 123 | — |
| Other operating charges (credits), net | 31 | 11 | (7) |
| Mainline operating special items, net | 787 | 712 | 709 |
| Regional operating special items, net | — | 3 | 13 |
| Operating special items, net | 787 | 715 | 722 |
| Mark-to-market adjustments on equity investments, net (8) | 104 | — | — |
| Debt refinancing and extinguishment charges | 13 | 22 | 49 |
| Other nonoperating credits, net | (4) | — | — |
| Nonoperating special items, net | 113 | 22 | 49 |
| Income tax special items (9) | 18 | — | — |
| Impact of the 2017 Tax Act (10) | — | 924 | — |
| Income tax special items, net | 18 | 924 | — |
Question:
What is American Airlines' labor contract expense in 2018?
Answer:
13