What was the sum of the three highest property and equipment in 2019?
{"Buildings and land": {"2019": 1693, "2018": 1737}, "Machinery and equipment": {"2019": 108945, "2018": 41330}, "Computer and communication equipment": {"2019": 29106, "2018": 24051}, "Furniture and fixtures": {"2019": 4119, "2018": 3203}, "Vehicles": {"2019": 262, "2018": 282}, "Leasehold improvements": {"2019": 33041, "2018": 20593}, "Construction in process": {"2019": 9089, "2018": 867}, "": {"2019": 186255, "2018": 92063}, "Less: Accumulated depreciation": {"2019": -78146, "2018": -60794}, "Property and equipment, net": {"2019": 108109, "2018": 31269}}
machinery_and_equipment_2019 = df["Machinery and equipment"]["2019"]
computer_and_communication_equipment_2019 = df["Computer and communication equipment"]["2019"]
leasehold_improvements_2019 = df["Leasehold improvements"]["2019"]
answer = machinery_and_equipment_2019 + computer_and_communication_equipment_2019 + leasehold_improvements_2019