A11235. Lazy Security Guard

Your security guard friend recently got a new job at a new security company. The company requires him to patrol an area of the city encompassing exactly $N$ city blocks, but they let him choose which blocks. That is, your friend must walk the perimeter of a region whose area is exactly $N$ blocks. Your friend is quite lazy and would like your help to find the shortest possible route that meets the requirements. The city is laid out in a square grid pattern, and is large enough that for the sake of the problem it can be considered infinite.

Input will consist of a single integer $N$ ( $1<=N<=10^{6}$ ), the number of city blocks that must be enclosed by the route.

Print the minimum perimeter that can be achieved.

Here are some possible shapes for the examples: