#include <bits/stdc++.h>
using namespace std;

#define pb push_back
#define sz(x) (int)x.size()
#define bit(n, k) (((n) >> (k)) & 1)

const int maxn = 1e2 + 10, mod = 1e9 + 7;

pair<int, int> arr[maxn];
bool mark[maxn];
vector<int> g[maxn];
int n;

void create(double d) {
	memset(mark, 0, sizeof mark);
	for (auto &i : g)
		i.clear();
	for (int i = 0; i < n; i++) {
		if (abs(arr[i].second + 100) < d) {
		   g[102].pb(i);
		   g[i].pb(102);
		}
		if (abs(arr[i].second - 100) < d) {
			g[104].pb(i);
			g[i].pb(104);
		}
		for (int j = i + 1; j < n; j++) {
			int dy = abs(arr[i].second - arr[j].second);
			int dx = abs(arr[i].first - arr[j].first);
			if (sqrt(dx * dx + dy * dy) < d) {
				g[i].pb(j);
				g[j].pb(i);
			}
		}
	}
}

void dfs(int u) {
	if (mark[u])
		return;
	mark[u] = 1;
	for (int v : g[u])
		dfs(v);
}

int main() {
	ios_base::sync_with_stdio(false);
	cin.tie(0);
	cin >> n;
	for (int i = 0; i < n; i++)
		cin >> arr[i].first >> arr[i].second;
	double l = 0.5;
	double r = 101;
	for (int i = 0; i < 30; i++) {
		create(2.0 * (r + l) / 2);
		dfs(102);
		if (mark[104])
			r = (r + l) / 2;
		else
			l = (r + l) / 2;
	}
	cout << setprecision(10) << (l + r) / 2;
	return 0;
}

#include <bits/stdc++.h>

// #include <atcoder/all>

using namespace std;
// using namespace atcoder;

#define DEBUG(x) cerr<<#x<<": "<<x<<endl;
#define DEBUG_VEC(v) cerr<<#v<<":";for(int i=0;i<v.size();i++) cerr<<" "<<v[i]; cerr<<endl;
#define DEBUG_MAT(v) cerr<<#v<<endl;for(int i=0;i<v.size();i++){for(int j=0;j<v[i].size();j++) {cerr<<v[i][j]<<" ";}cerr<<endl;}
typedef long long ll;
// #define int ll
 
#define vi vector<int>
#define vl vector<ll>
#define vii vector< vector<int> >
#define vll vector< vector<ll> >
#define vs vector<string>
#define pii pair<int,int>
#define pis pair<int,string>
#define psi pair<string,int>
#define pll pair<ll,ll>
template<class S, class T> pair<S, T> operator+(const pair<S, T> &s, const pair<S, T> &t) { return pair<S, T>(s.first + t.first, s.second + t.second); }
template<class S, class T> pair<S, T> operator-(const pair<S, T> &s, const pair<S, T> &t) { return pair<S, T>(s.first - t.first, s.second - t.second); }
template<class S, class T> ostream& operator<<(ostream& os, pair<S, T> p) { os << "(" << p.first << ", " << p.second << ")"; return os; }
#define X first
#define Y second
#define rep(i,n) for(int i=0;i<(int)(n);i++)
#define rep1(i,n) for(int i=1;i<=(int)(n);i++)
#define rrep(i,n) for(int i=(int)(n)-1;i>=0;i--)
#define rrep1(i,n) for(int i=(int)(n);i>0;i--)
#define REP(i,a,b) for(int i=a;i<b;i++)
#define in(x, a, b) (a <= x && x < b)
#define all(c) c.begin(),c.end()
template<class T> bool chmax(T &a, const T &b) { if (a<b) { a = b; return 1; } return 0; }
template<class T> bool chmin(T &a, const T &b) { if (a>b) { a = b; return 1; } return 0; }
#define UNIQUE(v) v.erase(std::unique(v.begin(), v.end()), v.end());
const ll inf = 1000000001;
const ll INF = (ll)1e18 + 1;
const long double pi = 3.1415926535897932384626433832795028841971L;
#define Sp(p) cout<<setprecision(25)<< fixed<<p<<endl;
// int dx[4] = {1, 0, -1, 0}, dy[4] = {0, 1, 0, -1};
// int dx2[8] = { 1,1,0,-1,-1,-1,0,1 }, dy2[8] = { 0,1,1,1,0,-1,-1,-1 };
vi dx = {1, 0, -1, 0}, dy = {0, 1, 0, -1};
// vi dx2 = { 1,1,0,-1,-1,-1,0,1 }, dy2 = { 0,1,1,1,0,-1,-1,-1 };
#define fio() cin.tie(0); ios::sync_with_stdio(false);
const ll MOD = 1000000007;
// const ll MOD = 998244353;
// #define mp make_pair
//#define endl '\n'

double distance(pii a, pii b) {
    return sqrt((a.first - b.first) * (a.first - b.first) + (a.second - b.second) * (a.second - b.second));
}

signed main() {
    fio();

    int n;
    cin >> n;
    vector<pii> yx(n);
    rep (i, n) cin >> yx[i].second >> yx[i].first;
    sort(all(yx));

    double ok = 0, ng = 100;
    rep (_, 200) {
        double r = (ok + ng) / 2;
        bool update_flag = true;
        vector<bool> dp(n);
        while (update_flag) {
            update_flag = false;
            rep (i, n) {
                if (yx[i].first + 100 < 2 * r) {
                    if (not dp[i]) {
                        dp[i] = true;
                        update_flag = true;
                    }
                }
                rep (j, n) {
                    if (dp[j]) {
                        double dist = distance(yx[i], yx[j]);
                        if (dist < 2 * r) {
                            if (not dp[i]) {
                                dp[i] = true;
                              	update_flag = true;
                            }
                        }
                    }
                }
            }
        }
        bool flag = true;
        rep (i, n) {
            if (dp[i]) {
                if (100 - yx[i].first < 2 * r) {
                    flag = false;
                }
            }
        }
        (flag ? ok : ng) = r;
    }
    Sp(ok);
}