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
There are cakes placed at equal intervals on a round table. Igor walks around the table and eats every third cake he encounters (each cake can be encountered multiple times). When there were no cakes left on the table, he noticed that the last cake he took was the same one he encountered first, and he had walked exactly seven laps around the table. How many cakes were there?
user
9
rule
There are cakes placed at equal intervals on a round table. Igor walks around the table and eats every third cake he encounters (each cake can be encountered multiple times). When there were no cakes left on the table, he noticed that the last cake he took was the same one he encountered first, and he had walked exactly seven laps around the table. How many cakes were there?
train