codeforces 859B B. Lazy Security Guard

B. Lazy Security Guard

time limit per test

2 seconds

memory limit per test

256 megabytes

input

standard input

output

standard output

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:

题目大意（来自百度翻译。。。。。。）：你的保安的朋友最近买了一个新的工作在一个新的安全公司。该公司要求他在城市的一个区域巡逻，包括N个街区，但他们让他选择哪些街区。那就是，你的朋友要走一个区域的周边地区正是N块。你的朋友很懒，希望你的帮助能找到符合要求的最短路线。这座城市的布局为正方形网格，规模很大，为了解决这个问题，它可以被认为是无限的。

其实看图就能明白，它是要求几个小正方形拼起来以后周长最小是多少

#include<bits/stdc++.h>using namespace std;int main(){int n;while(cin>>n){cout<<2*(ceil(2*sqrt(n)))<<endl;}}