What was the sum of the EBITDA in 2018?
{"Software Solutions": {"2018": 567.2, "2017": 516.5, "$": 50.7, "%": 10.0}, "Data and Analytics": {"2018": 39.5, "2017": 38.4, "$": 1.1, "%": 3.0}}
ebitda_2018 = df["Software Solutions"]["2018"] + df["Data and Analytics"]["2018"]
answer = ebitda_2018