///////////////////////////////////////////////////////////////////////////////

#include <bits/stdc++.h>
#include <unistd.h>
#include <time.h>
#include <sys/time.h>

using namespace std;

///////////////////////////////////////////////////////////////////////////////

#define DEBUG 0

#define pb push_back
#define V vector
#define M unordered_map
#define S static

#define rep(i,n) for(ll i=0LL; i<n; ++i)
#define srep(i,s,n) for(ll i=s; i<n; ++i)
#define rrep(i,n) for(ll i=n-1LL; i>=0LL; --i)
#define ALL(a) (a).begin(),(a).end()
#define RALL(a) (a).rbegin(),(a).rend()
#define CIN(x) do { \
        assert(!cin.eof()); \
        cin >> x; \
        assert(!cin.fail()); \
} while(0);
#if DEBUG
#define debug_print(...) _debug_print(__VA_ARGS__)
#define debug_printf(...) printf(__VA_ARGS__)
#define debug_print_time _debug_print_time
#else // DEBUG
#define debug_print(...)
#define debug_printf(...)
#define debug_print_time
#endif // DEBUG

typedef long long ll;
typedef unsigned long long ull;
typedef tuple<ll, ll> t2;
typedef tuple<ll, ll, ll> t3;
typedef tuple<ll, ll, ll, ll> t4;
typedef tuple<ll, ll, ll, ll, ll> t5;
template <typename T>
using priority_queue_incr = priority_queue<T, V<T>, greater<T> >;

///////////////////////////////////////////////////////////////////////////////

template <typename TT, typename T>
T get_m(M<TT, T> &m, TT k, T default_value)
{
    if (m.find(k) == m.end()) return m[k] = default_value;
    return m[k];
}

template <typename TT, typename T>
void incr_m(M<TT, T> &m, TT k)
{
    if (m.find(k) == m.end()) m[k] = 0;
    m[k]++;
}

template <typename TT, typename T>
void incr_m(map<TT, T> &m, TT k)
{
    if (m.find(k) == m.end()) m[k] = 0;
    m[k]++;
}

void llin(ll &a)
{
    CIN(a);
}

void llinl1(V<ll> &v, ll count)
{
    for (ll i = 0LL; i < count; ++i) {
        ll a;
        CIN(a);
        v.push_back(a);
    }
}

void llinl2(V<t2> &v, ll count)
{
    for (ll i = 0LL; i < count; ++i) {
        ll a, b;
        CIN(a >> b);
        v.push_back(t2(a, b));
    }
}

void llinl3(V<t3> &v, ll count)
{
    for (ll i = 0LL; i < count; ++i) {
        ll a, b, c;
        CIN(a >> b >> c);
        v.push_back(t3(a, b, c));
    }
}

void llinl4(V<t4> &v, ll count)
{
    for (ll i = 0LL; i < count; ++i) {
        ll a, b, c, d;
        CIN(a >> b >> c >> d);
        v.push_back(t4(a, b, c, d));
    }
}

void llina(V<ll> &v, ll count)
{
    llinl1(v, count);
}

template <typename T>
void sort(V<T> &v)
{
    sort(v.begin(), v.end());
}

template <typename T>
void sort_reverse(V<T> &v)
{
    sort(v.begin(), v.end(), greater<T>());
}

template <typename T>
void _debug_print(T x)
{
    cout << x << endl;
}

void _debug_print(const t2 &x)
{
    ll x1 = get<0>(x);
    ll x2 = get<1>(x);
    cout << "-- " << x1 << " -- " << x2 << endl;
}

void _debug_print(const t3 &x)
{
    ll x1 = get<0>(x);
    ll x2 = get<1>(x);
    ll x3 = get<2>(x);
    cout << "-- " << x1 << " -- " << x2 << " -- " << x3 << endl;
}

void _debug_print(const t4 &x)
{
    ll x1 = get<0>(x);
    ll x2 = get<1>(x);
    ll x3 = get<2>(x);
    ll x4 = get<3>(x);
    cout << "-- " << x1 << " -- " << x2
         << " -- " << x3 << " -- " << x4 << endl;
}

template <typename T>
void _debug_print(T xarray[], ll n)
{
    rep (i, n) _debug_print(xarray[i]);
}

template <typename T>
void _debug_print(const V<T> &xlist)
{
    for (auto x : xlist) {
        cout << "-- ";
        _debug_print(x);
    }
}

template <typename T>
void _debug_print(const set<T> &xset)
{
    for (auto x : xset) {
        cout << "-- ";
        _debug_print(x);
    }
}

template <typename TT, typename T>
void _debug_print(const M<TT, T> &xlist)
{
    for (auto x : xlist) {
        TT k = x.first;
        T v = x.second;
        cout << "====" << endl;
        cout << "K=";
        _debug_print(k);
        cout << "V=";
        _debug_print(v);
    }
}

template <typename TT, typename T>
void _debug_print(const map<TT, T> &xlist)
{
    for (auto x : xlist) {
        TT k = x.first;
        T v = x.second;
        cout << "====" << endl;
        cout << "K=";
        _debug_print(k);
        cout << "V=";
        _debug_print(v);
    }
}

void _debug_print_time(const char *prefix)
{
    struct timeval tv;
    gettimeofday(&tv, NULL);
    struct tm *tm = localtime(&tv.tv_sec);
    debug_printf("-- %s %02d:%02d:%02d.%06ld\n",
                  prefix, tm->tm_hour, tm->tm_min, tm->tm_sec, tv.tv_usec);
}

///////////////////////////////////////////////////////////////////////////////

void _main();
int main()
{
    cout << setprecision(12);
#if !DEBUG
    ios::sync_with_stdio(false);
    cin.tie(0);
#endif

    _main();
    return 0;
}

typedef tuple<double, double> dd;

bool find(dd &p1, dd &p2, double x1, double y1, double x2, double y2, double r)
{
    double d = sqrt((x1-x2)*(x1-x2) + (y1-y2)*(y1-y2));
    if (d > r * 2.0) return false;

    x2 -= x1;
    y2 -= y1;
    double rad = atan2(y2, x2);
    double rad1 = rad + M_PI;
    double rad2 = rad1 + M_PI;

    debug_printf("rad=%lf rad1=%lf rad2=%lf\n", rad, rad1, rad2);

    double left = rad;
    double right = rad1;
    double arad1 = rad;

    rep (xxx, 100) {
        double now = (left+right)/2.0;
        //debug_printf("xxx %lf\n", now);
        double xx = r * cos(now);
        double yy = r * sin(now);
        double dd = sqrt((xx-x2)*(xx-x2) + (yy-y2)*(yy-y2));
        if (dd <= r) {
            arad1 = max(arad1, now);
            left = now;
        }
        else {
            right = now;
        }
    }

    left = rad1;
    right = rad2;
    double arad2 = rad2;

    rep (xxx, 100) {
        double now = (left+right)/2.0;
        double xx = r * cos(now);
        double yy = r * sin(now);
        double dd = sqrt((xx-x2)*(xx-x2) + (yy-y2)*(yy-y2));
        if (dd <= r) {
            arad2 = min(arad2, now);
            right = now;
        }
        else {
            left = now;
        }
    }

    double px1 = r * cos(arad1);
    double py1 = r * sin(arad1);
    p1 = dd(px1+x1, py1+y1);

    debug_printf("arad1=%lf (%lf, %lf)\n", arad1, px1, py1);
    debug_printf("arad1=%lf (%lf, %lf)\n", arad1, px1+x1, py1+y1);

    double px2 = r * cos(arad2);
    double py2 = r * sin(arad2);
    p2 = dd(px2+x1, py2+y1);

    debug_printf("arad2=%lf (%lf, %lf)\n", arad2, px2+x1, py2+y1);

    return true;
}

bool judge(const V<t2> &xylist, ll n, double r)
{
    debug_printf("------- x1\n");

    V<dd> points;
    rep (i, n) srep (j, i+1, n) {
        double x1 = get<0>(xylist[i]);
        double y1 = get<1>(xylist[i]);
        double x2 = get<0>(xylist[j]);
        double y2 = get<1>(xylist[j]);
        dd p1, p2;
        if (!find(p1, p2, x1, y1, x2, y2, r)) return false;
        points.pb(p1);
        points.pb(p2);
    }

    debug_printf("------- x2\n");
    for (auto ppp : points) {
        debug_printf("%lf ", get<0>(ppp));
        debug_printf("%lf\n", get<1>(ppp));
    }

    for (auto p : points) {
        double px = get<0>(p);
        double py = get<1>(p);
        bool ng = false;
        for (auto xy : xylist) {
            double x = get<0>(xy);
            double y = get<1>(xy);
            double d = sqrt((x-px)*(x-px) + (y-py)*(y-py));
            if (d > r + 1e-7) ng = true;
        }
        if (!ng) {
            debug_printf("---- true\n");
            return true;
        }
    }

    debug_printf("---- false\n");
    return false;
}

void _main()
{
    ll n; llin(n);
    V<t2> xylist; llinl2(xylist, n);

    double left = 0;
    double right = 5000;
    double ans = right;

    rep (xxx, 100) {
        double now = (left+right)/2.0;
        debug_printf("XXXXX left=%lf right=%lf now=%lf\n", left, right, now);
        if (judge(xylist, n, now)) {
            ans = min(ans, now);
            right = now;
        }
        else {
            left = now;
        }
    }

    debug_printf("-------------------- ans\n");
    cout << ans << endl;
}

///////////////////////////////////////////////////////////////////////////////


Measured memory_bytes: 4472