Carla works at a food bank and she currently has stocked up 2000 cans of food. One day, 500 people showed up and took 1 can of food each. Carla had to then restock 1500 more cans to keep up with demand. The next day, 1000 people showed up and took 2 cans of food each. Carla restocked again with 3000 cans of food this time. How many cans of food did Carla give away?
Please reason step by step, and put your final answer within \boxed{}.
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