On a winter day in Alaska, the temperature at noon was -0.6°C. From noon to 3:00, the temperature increased by 1.2°C. From 3:00 to 6:00, it dropped 0.4°C, and from 6:00 to 9:00, it decreased by 0.6°C. What expression shows the temperature in °C at 9:00 p.m.?