You are a helpful assistant that can solve the given question step by step with the help of the wikipedia search tool and python interpreter tool. Given a question, you need to first think about the reasoning process in the mind and then provide the answer. During thinking, you can invoke the wikipedia search tool to search and python interpreter tool to calculate the math problem for fact information about specific topics if needed. The reasoning process and answer are enclosed within <think> </think> and <answer> </answer> tags respectively, and the search query and result are enclosed within <search> </search> and <result> </result> tags respectively. For example, <think> This is the reasoning process. </think> <search> search query here </search> <result> search result here </result> <think> This is the reasoning process. </think> <python> python code here </python> <result> python interpreter result here </result> <think> This is the reasoning process. </think> <answer> The final answer is \[ oxed{answer here} \] </answer>. In the last part of the answer, the final exact answer is enclosed within oxed{} with latex format.
system
A community plans to organize three activities, "Book Club," "Fun Sports," and "Environmental Theme Painting," in order to enrich the lives of residents. A total of 120 people have signed up for the activities, with each resident participating in at most two activities. It is known that 80 people participate in the "Book Club," 50 people participate in "Fun Sports," and 40 people participate in "Environmental Theme Painting." Additionally, 20 people participate in both the "Book Club" and "Fun Sports," and 10 people participate in both "Fun Sports" and "Environmental Theme Painting." Find the number of people who participate in both the "Book Club" and "Environmental Theme Painting."
user
20
rule
A community plans to organize three activities, "Book Club," "Fun Sports," and "Environmental Theme Painting," in order to enrich the lives of residents. A total of 120 people have signed up for the activities, with each resident participating in at most two activities. It is known that 80 people participate in the "Book Club," 50 people participate in "Fun Sports," and 40 people participate in "Environmental Theme Painting." Additionally, 20 people participate in both the "Book Club" and "Fun Sports," and 10 people participate in both "Fun Sports" and "Environmental Theme Painting." Find the number of people who participate in both the "Book Club" and "Environmental Theme Painting."
train