#include <cstdio>
#include <iostream>
#include <vector>
#include <map>
#include <set>
#include <string>
#include <cstring>
#include <sstream>
#include <algorithm>
#include <functional>
#include <queue>
#include <stack>
#include <cmath>
#include <iomanip>
using namespace std;
inline int toInt(string s) { int v; istringstream sin(s); sin >> v; return v; }
template<class T> inline string toString(T x) { ostringstream sout; sout << x; return sout.str(); }
template<class T> inline T sqr(T x) { return x*x; }
typedef pair<int, int> P;
typedef long long ll;
typedef unsigned long long ull;

#define rep(i,n)  for(int (i) = 0;(i) < (n);(i)++)
#define clr(a) memset((a), 0 ,sizeof(a))
#define mclr(a) memset((a), -1 ,sizeof(a))
#define all(a)  (a).begin(),(a).end()
#define rall(a) (a).rbegin(), (a).rend()
#define sz(a) (sizeof(a))
#define Fill(a,v) fill((int*)a,(int*)(a+(SZ(a)/SZ(*(a)))),v)
bool cheak(int x, int y, int xMax, int yMax){ return x >= 0 && y >= 0 && xMax > x && yMax > y; }
const int dx[4] = { -1, 0, 1, 0 }, dy[4] = { 0, 1, 0, -1 };
const int mod = 1000000007;
const int INF = 2147483647;

const int M = 1010;
int n;
ll x[M], y[M];

struct UnionFind
{
	vector<int> data;
	UnionFind(int size) :data(size, -1){}
	bool unionSet(int x, int y){
		x = root(x), y = root(y);
		if (x != y){
			if (data[y] < data[x])swap(x,y);
			data[x] += data[y]; data[y] = x;
		}
		return x != y;
	}
	bool findSet(int x, int y){
		return root(x) == root(y);
	}
	int root(int x){
		return data[x] < 0 ? x : data[x] = root(data[x]);
	}
	int size(int x){
		return -data[root(x)];
	}

};

bool can(ll m){
	m = m*10;

	UnionFind uf(n);
	rep(i, n)rep(j, n){
		if (sqr(x[i] - x[j])+sqr(y[i] - y[j]) <= m*m)
		uf.unionSet(i,j);
	}
	
	if(!uf.findSet(0,n-1))return false;
	return true;
}

int main()
{
	cin >> n;
	rep(i, n){
		cin >> x[i] >> y[i];
	}

	ll r=INF/10,l=0, m;
	while (1){
		m = (r+l)/2;

		if (can(m)){
			if (!can(m-1))
				break;
			r = m;
		}
		else{
			l = m;
		}
	}

	cout << m*10 << endl;

	return 0;
}