#define _USE_MATH_DEFINES
#include "bits/stdc++.h"
using namespace std;
#define FOR(i,j,k) for(int (i)=(j);(i)<(int)(k);++(i))
#define rep(i,j) FOR(i,0,j)
#define each(x,y) for(auto &(x):(y))
#define mp make_pair
#define MT make_tuple
#define all(x) (x).begin(),(x).end()
#define debug(x) cout<<#x<<": "<<(x)<<endl
#define smax(x,y) (x)=max((x),(y))
#define smin(x,y) (x)=min((x),(y))
#define MEM(x,y) memset((x),(y),sizeof (x))
#define sz(x) (int)(x).size()
#define RT return
using ll = long long;
using pii = pair<int, int>;
using vi = vector<int>;
using vll = vector<ll>;

class UnionFind {
    int cnt;
    vector<int> par, rank, size;
public:
    UnionFind() {}
    UnionFind(int _n) :cnt(_n), par(_n), rank(_n), size(_n, 1) {
        for (int i = 0; i<_n; ++i) par[i] = i;
    }
    int find(int k) {
        return (k == par[k]) ? k : (par[k] = find(par[k]));
    }
    int operator[](int k) {
        return find(k);
    }
    int getSize(int k) {
        return size[find(k)];
    }
    void unite(int x, int y) {
        x = find(x); y = find(y);
        if (x == y) return;
        --cnt;
        if (rank[x] < rank[y]) {
            par[x] = y;
            size[y] += size[x];
        } else {
            par[y] = x;
            size[x] += size[y];
            if (rank[y] == rank[x]) ++rank[x];
        }
    }
    int count() {
        return cnt;
    }
};

void solve() {
    int N;
    cin >> N;
    vi X(N), Y(N);
    rep(i, N) cin >> X[i] >> Y[i];
    double ng = 100, ok = 0;
    rep(ITER, 60) {
        UnionFind uf(N + 2);
        double r = (ng + ok) / 2;
        rep(i, N) {
            if (100 - Y[i] < 2 * r)uf.unite(i, N);
            if (Y[i] + 100 < 2 * r)uf.unite(i, N + 1);
            rep(j, i) {
                if (hypot(X[i] - X[j], Y[i] - Y[j]) < 2 * r) {
                    uf.unite(i, j);
                }
            }
        }
        (uf[N] == uf[N + 1] ? ng : ok) = r;
    }
    cout << ok << endl;
}

int main() {
	ios::sync_with_stdio(false);
	cin.tie(0);
	cout << fixed << setprecision(15);
	solve();
	return 0;
}
#include <bits/stdc++.h>

using namespace std;

using int64 = long long;
const int mod = 1e9 + 7;
// const int mod = 998244353;

const int64 infll = (1LL << 62) - 1;
const int inf = (1 << 30) - 1;

struct IoSetup {
  IoSetup() {
    cin.tie(nullptr);
    ios::sync_with_stdio(false);
    cout << fixed << setprecision(10);
    cerr << fixed << setprecision(10);
  }
} iosetup;


template< typename T1, typename T2 >
ostream &operator<<(ostream &os, const pair< T1, T2 > &p) {
  os << p.first << " " << p.second;
  return os;
}

template< typename T1, typename T2 >
istream &operator>>(istream &is, pair< T1, T2 > &p) {
  is >> p.first >> p.second;
  return is;
}

template< typename T >
ostream &operator<<(ostream &os, const vector< T > &v) {
  for(int i = 0; i < (int) v.size(); i++) {
    os << v[i] << (i + 1 != v.size() ? " " : "");
  }
  return os;
}

template< typename T >
istream &operator>>(istream &is, vector< T > &v) {
  for(T &in : v) is >> in;
  return is;
}

template< typename T1, typename T2 >
inline bool chmax(T1 &a, T2 b) { return a < b && (a = b, true); }

template< typename T1, typename T2 >
inline bool chmin(T1 &a, T2 b) { return a > b && (a = b, true); }

template< typename T = int64 >
vector< T > make_v(size_t a) {
  return vector< T >(a);
}

template< typename T, typename... Ts >
auto make_v(size_t a, Ts... ts) {
  return vector< decltype(make_v< T >(ts...)) >(a, make_v< T >(ts...));
}

template< typename T, typename V >
typename enable_if< is_class< T >::value == 0 >::type fill_v(T &t, const V &v) {
  t = v;
}

template< typename T, typename V >
typename enable_if< is_class< T >::value != 0 >::type fill_v(T &t, const V &v) {
  for(auto &e : t) fill_v(e, v);
}

template< typename F >
struct FixPoint : F {
  FixPoint(F &&f) : F(forward< F >(f)) {}

  template< typename... Args >
  decltype(auto) operator()(Args &&... args) const {
    return F::operator()(*this, forward< Args >(args)...);
  }
};

template< typename F >
inline decltype(auto) MFP(F &&f) {
  return FixPoint< F >{forward< F >(f)};
}

/**
 * @brief Union-Find
 * @docs docs/union-find.md
 */
struct UnionFind {
  vector< int > data;

  UnionFind() = default;

  explicit UnionFind(size_t sz) : data(sz, -1) {}

  bool unite(int x, int y) {
    x = find(x), y = find(y);
    if(x == y) return false;
    if(data[x] > data[y]) swap(x, y);
    data[x] += data[y];
    data[y] = x;
    return true;
  }

  int find(int k) {
    if(data[k] < 0) return (k);
    return data[k] = find(data[k]);
  }

  int size(int k) {
    return -data[find(k)];
  }

  bool same(int x, int y) {
    return find(x) == find(y);
  }
};


int main() {
  int N;
  cin >> N;
  vector< int > X(N), Y(N);
  for(int i = 0; i < N; i++) {
    cin >> X[i] >> Y[i];
  }
  vector< tuple< double, int, int > > es;
  for(int i = 0; i < N; i++) {
    for(int j = 0; j < i; j++) {
      es.emplace_back(hypot(X[i] - X[j], Y[i] - Y[j]), i, j);
    }
    es.emplace_back(100 - Y[i], i, N);
    es.emplace_back(Y[i] + 100, i, N + 1);
  }
  sort(es.begin(), es.end());
  UnionFind uf(N + 2);
  for(auto[dist, x, y]:es) {
    uf.unite(x, y);
    if(uf.find(N) == uf.find(N + 1)) {
      cout << dist / 2 << "\n";
      return 0;
    }
  }
}
