Sarah is planning a road trip. She drives 120 miles to visit her friend, then another 80 miles to reach a national park. From there, she drives to her cousin's house, which is 50 miles away, and finally returns home, which is 200 miles from her cousin's house. After returning home, she realizes she wants to visit another friend who lives 30 miles away. If she has already driven 480 miles, how many miles did she drive to visit her final friend? Let's think step by step and output the final answer within \boxed{}.
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