What is the total operating expense of fiscal years 2018 and 2019?
{"(In millions, except for percentages) -- Sales and marketing": {"2019": 1493, "2018": 1593, "Dollars": -100, "Percent": -6}, "(In millions, except for percentages) -- Research and development": {"2019": 913, "2018": 956, "Dollars": -43, "Percent": -4}, "(In millions, except for percentages) -- General and administrative": {"2019": 447, "2018": 574, "Dollars": -127, "Percent": -22}, "(In millions, except for percentages) -- Amortization of intangible assets": {"2019": 207, "2018": 220, "Dollars": -13, "Percent": -6}, "(In millions, except for percentages) -- Restructuring, transition and other costs": {"2019": 241, "2018": 410, "Dollars": -169, "Percent": -41}, "(In millions, except for percentages) -- Total": {"2019": 3301, "2018": 3753, "Dollars": -452, "Percent": -12}}
total_2019 = df["(In millions, except for percentages) -- Total"]["2019"]
total_2018 = df["(In millions, except for percentages) -- Total"]["2018"]
answer = total_2019 + total_2018