write a go solution for Description:
Let's call a set of positive integers a_1,a_2,...,a_k quadratic if the product of the factorials of its elements is a square of an integer, i. e. prodlimits_i=1^ka_i!=m^2, for some integer m.

You are given a positive integer n.

Your task is to find a quadratic subset of a set 1,2,...,n of maximum size. If there are multiple answers, print any of them.

Input Format:
A single line contains a single integer n (1<=n<=10^6).

Output Format:
In the first line, print a single integer — the size of the maximum subset. In the second line, print the subset itself in an arbitrary order.

Note:
None. Output only the code with no comments, explanation, or additional text.