A contractor needs to paint the exterior surfaces of a rectangular building with a length of 20 meters, a width of 15 meters, and a height of 10 meters. The building has 5 identical windows, each measuring 1.5 meters by 2 meters, that do not need to be painted. Calculate the total surface area that needs to be painted in square meters. Let's think step by step and output the final answer within \boxed{}.
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