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

Input will consist of a single integer N (1 ≤ N ≤ 106), the number of city blocks that must be enclosed by the route.

Output

Print the minimum perimeter that can be achieved.

Examples

Input

4


Output

8


Input

11


Output

14


Input

22


Output

20

Note

Here are some possible shapes for the examples:

<image>
import java.util.Scanner;

public class codeForces2 {
	public static void main(String[] args) {
		Scanner in = new Scanner(System.in);
		int n = in.nextInt();

		int square = 0;
		int justOver = 0;

		if(n == 3) {
			System.out.println(8);
			System.exit(0);
		}
		
		
		
		for (int i = 1; i < 1001; i++) {
			if (i * i == n) {
				square = i;
			}
			else if (i * i < n) {
				justOver = i;

			}
		}

		if (square != 0) {
			System.out.println(4 * square);
			System.exit(0);
		}
		else {
			int retVal = justOver * 4;
			int amountOver = justOver * 4;

			int blocksLeft = n - (justOver * justOver);
			for (int i = 0; i < blocksLeft; i++) {
				if (i == 0) {
					retVal += 2;

				}
				else if (i == justOver) {
					retVal += 2;
				}

			}
			System.out.println(retVal);
		}

	}
}
