#include <cstdio>
#include <cmath>
#include <algorithm>
using namespace std;

struct point
{
	int x,y;
};

int main()
{
	int n,cs=1,i,arr[100],tx,ty;
	double sum=-1.0,ts;
	point points[100];
	scanf("%d",&n);
		for(i=0;i<2*n;i++)
		  scanf("%d%d",&points[i].x,&points[i].y);
		
		for(i=0;i<2*n;i++)
		  arr[i] = i;
		sum=-1.0;
		do{
			ts = 0.0;
			for(i=0;i<n;i++)
			{
				tx = (points[arr[2*i]].x - points[arr[2*i+1]].x);
				ty = (points[arr[2*i]].y - points[arr[2*i+1]].y);
			  ts += sqrt(tx*tx+ty*ty);
			}
			
			if(sum>ts || sum<0)
			  sum = ts;
		  }while(next_permutation(arr,arr+(2*n)));
		  printf("%.0lf\n",sum);
}