CF1406E Deleting Numbers

This is an interactive problem. There is an unknown integer $ x $ ( $ 1\le x\le n $ ). You want to find $ x $ . At first, you have a set of integers $ \{1, 2, \ldots, n\} $ . You can perform the following operations no more than $ 10000 $ times: - A $ a $ : find how many numbers are multiples of $ a $ in the current set. - B $ a $ : find how many numbers are multiples of $ a $ in this set, and then delete all multiples of $ a $ , but $ x $ will never be deleted (even if it is a multiple of $ a $ ). In this operation, $ a $ must be greater than $ 1 $ . - C $ a $ : it means that you know that $ x=a $ . This operation can be only performed once. Remember that in the operation of type B $ a>1 $ must hold. Write a program, that will find the value of $ x $ .

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Note that to make the sample more clear, we added extra empty lines. You shouldn't print any extra empty lines during the interaction process. In the first test $ n=10 $ and $ x=4 $ . Initially the set is: $ \{1,2,3,4,5,6,7,8,9,10\} $ . In the first operation, you ask how many numbers are multiples of $ 4 $ and delete them. The answer is $ 2 $ because there are two numbers divisible by $ 4 $ : $ \{4,8\} $ . $ 8 $ will be deleted but $ 4 $ won't, because the number $ x $ will never be deleted. Now the set is $ \{1,2,3,4,5,6,7,9,10\} $ . In the second operation, you ask how many numbers are multiples of $ 2 $ . The answer is $ 4 $ because there are four numbers divisible by $ 2 $ : $ \{2,4,6,10\} $ . In the third operation, you ask how many numbers are multiples of $ 8 $ . The answer is $ 0 $ because there isn't any number divisible by $ 8 $ in the current set. In the fourth operation, you know that $ x=4 $ , which is the right answer.