#include <cstdio>

#include <cstdlib>

#include <cmath>

#include <algorithm>

using namespace std;

const int N=5005;

struct P { int x, y; }a[N];

int n;

inline int rand(int x, int y) { return x+(rand()%(y-x+1)); }

inline double sqr(double x) { return x*x; }

inline double dis(double x1, double y1, double x2, double y2) { return sqrt(sqr(x1-x2)+sqr(y1-y2)); }

inline double getdis(double x, double y) {

	double ret=0;

	for(int i=0; i<n; ++i) ret+=dis(x, y, a[i].x, a[i].y);

	return ret;

}

double getnode(double x, double y, double T, double &xx, double &yy) {

	double tx, ty, dis, ret=1e300;

	for(int i=0; i<50; ++i) {

		tx=x+((double)rand(-100, 100)/100)*T;

		ty=y+((double)rand(-100, 100)/100)*T;

		dis=getdis(tx, ty);

		if(dis<ret) {

			ret=dis;

			xx=tx;

			yy=ty;

		}

	}

	return ret;

}

int main() {

	srand(1998);

	while(~scanf("%d", &n)) {

		double x=0, y=0, T=1e20, dE, tans, ans, nans, xx, yy;

		for(int i=0; i<n; ++i) scanf("%d%d", &a[i].x, &a[i].y), x+=a[i].x, y+=a[i].y;

		x/=n; y/=n;

		nans=ans=getdis(x, y);

		while(T>0.01) {

			tans=getnode(x, y, T, xx, yy);

			dE=nans-tans;

			if(dE>=0 || exp(dE/T)>(double)rand(1, 99999)/100000) {

				nans=tans; x=xx; y=yy; ans=min(ans, nans);

			}

			T*=0.9;

		}

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

	}

	return 0;

}