codeforces 859B

 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
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.


Example
Input
4
Output
8
Input
11
Output
14
Input
22
Output
20

Note
Here are some possible shapes for the examples:

题意：给出正方形的个数，拼到一起能够拼出最少的边；

思路：找规律，打表。

#include<stdio.h>
#include<iostream>
#include<algorithm>
#include<string.h>
#include<math.h>
using namespace std;
long long a[1100000];
int main()
{
    int n;
    a[0]=0;
    a[1]=4;
    a[2]=6;
    long long t=8;
    long long q=2;
    int i=3;
    while(1)
    {
        for(int j=0; j<q; j++)
        {
            a[i++]=t;
        }
        if(i>1000010)
            break;
        t+=2;
        for(int j=0; j<q; j++)
        {
            a[i++]=t;
        }
        q++;
        t+=2;
        if(i>1000010)
            break;
    }
//    for(int i=1;i<=25;i++)
//        cout<<a[i]<<endl;
    while(~scanf("%d",&n))
    {

        cout<<a[n]<<endl;
    }
}