Every student in the senior class is taking history or science. There are $200$ seniors in the class. If there are $126$ seniors taking history and $129$ seniors taking science, how many students are taking both history and science?
<|im_start|>system
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<|im_start|>user
Every student in the senior class is taking history or science. There are $200$ seniors in the class. If there are $126$ seniors taking history and $129$ seniors taking science, how many students are taking both history and science?
Please reason step by step, and put your final answer within \boxed{{}}.<|im_end|>
<|im_start|>assistant

user
55
Every student in the senior class is taking history or science. There are $200$ seniors in the class. If there are $126$ seniors taking history and $129$ seniors taking science, how many students are taking both history and science?
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