//

//  main.cpp

//  poj2420

//

//  Created by 陈加寿 on 16/2/13.

//  Copyright © 2016年 chenhuan001. All rights reserved.

//

#include <iostream>

#include <stdio.h>

#include <math.h>

#include <string.h>

#include <algorithm>

using namespace std;

struct Point

{

    int x,y;

}g[110];

#define eps 1e-6

double myrand()

{

    long long a=rand();

    long long b=rand();

    a = a*b%200000-100000;

    return ((double)a/10);

}

double fuc(double x,double y,int n)

{

    double sum=0;

    for(int i=0;i<n;i++)

        sum += sqrt( (x-g[i].x)*(x-g[i].x)+(y-g[i].y)*(y-g[i].y) );//不是哈密顿距离

    return sum;

}

double cold(int n)

{

    double tx=0,ty=0;

    double K=1;

    double min=fuc(tx,ty,n);

    while(K>eps)

    {

        double xx,yy;

        xx=myrand()*K+tx;

        yy=myrand()*K+ty;

        double tmp=fuc(xx,yy,n);

        if( tmp < min )

        {

            min=tmp;

            tx=xx;

            ty=yy;

        }

        K*=0.98;

    }

    return min;

}

int main(int argc, const char * argv[]) {

    int n;

    scanf("%d",&n);

    for(int i=0;i<n;i++)

    {

        scanf("%d%d",&g[i].x,&g[i].y);

    }

    double ans = 1e9;

    ans = min(ans,cold(n));

    printf("%.0lf\n",ans);

    return 0;

}