write a go solution for Description:
This is an interactive problem.

There is an unknown integer x (1<=x<=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.

Input Format:
The first line contains one integer n (1<=n<=10^5). The remaining parts of the input will be given throughout the interaction process.

Output Format:
None

Note:
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.. Output only the code with no comments, explanation, or additional text.