In a school, there are 50 students who are part of at least one of three clubs: Science Club, Math Club, and Art Club. 28 students are in the Science Club, 22 students are in the Math Club, and 18 students are in the Art Club. If 12 students are in both the Science and Math Clubs, 7 students are in both the Science and Art Clubs, and 5 students are in both the Math and Art Clubs, how many students are in all three clubs? Let's think step by step and output the final answer within \boxed{}.
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