Assuming that "Cost of Revenue" is the only variable cost, Net income is $18,485, and using the formula Revenue- Cost of Revenue Fixed Costs = Net Income, what is Facebook's total fixed costs in 2019?

\begin{tabular}{lrr} \cline { 2 - 2 } Revenue & \multicolumn{2}{c}{2019} \\ \cline { 2 - 2 } Costs and expenses: & $ & 70,697 \\ \hline Cost of revenue & 12,770 \\ \hline Research and development & 13,600 \\ \hline Marketing and sales & 9,876 \\ \hline General and administrative & 10,465 \\ \hline Total costs and expenses & 46,711 \\ \hline Income from operations & 23,986 \\ \cline { 2 - 2 } \end{tabular}