// #pragma GCC
// target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,avx2,avx512f")
#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx")
#pragma GCC optimize("O3")
#pragma GCC optimize("unroll-loops")
#include <immintrin.h>

#include <algorithm>
#include <bitset>
#include <cassert>
#include <cmath>
#include <complex>
#include <functional>
#include <iomanip>
#include <iostream>
#include <list>
#include <map>
#include <memory>
#include <numeric>
#include <queue>
#include <random>
#include <set>
#include <stack>
#include <string>
#include <unordered_map>
#include <unordered_set>
#include <vector>
#ifdef DEBUG
#include "./CompetitiveProgrammingCpp/Timer.hpp"
#include "./CompetitiveProgrammingCpp/debug.hpp"
#include "./CompetitiveProgrammingCpp/sample.hpp"
#else
#define dump(...)
#endif

/* macro */
#define FOR(i, b, e) for (ll i = (ll)(b); i < (ll)(e); ++i)
#define RFOR(i, b, e) for (ll i = (ll)(e - 1); i >= (ll)(b); --i)
#define REP(i, n) FOR(i, 0, n)
#define RREP(i, n) RFOR(i, 0, n)
#define REPC(x, c) for (const auto& x : (c))
#define REPI2(it, b, e) for (auto it = (b); it != (e); ++it)
#define REPI(it, c) REPI2(it, (c).begin(), (c).end())
#define RREPI(it, c) REPI2(it, (c).rbegin(), (c).rend())
#define REPI_ERACE2(it, b, e) for (auto it = (b); it != (e);)
#define REPI_ERACE(it, c) REPI_ERACE2(it, (c).begin(), (c).end())
#define ALL(x) (x).begin(), (x).end()
#define cauto const auto&
/* macro func */
template <class T>
inline auto sort(T& t) {
  std::sort(ALL(t));
}
template <class T>
inline auto rsort(T& t) {
  std::sort((t).rbegin(), (t).rend());
}
template <class T>
inline auto unique(T& t) {
  (t).erase(unique((t).begin(), (t).end()), (t).end());
}
template <class T, class S>
inline auto chmax(T& t, const S& s) {
  if (s > t) {
    t = s;
    return true;
  }
  return false;
}
template <class T, class S>
inline auto chmin(T& t, const S& s) {
  if (s < t) {
    t = s;
    return true;
  }
  return false;
}
inline auto BR() { std::cout << "\n"; }

/* type define */
using ll = long long;
using PAIR = std::pair<ll, ll>;
using VS = std::vector<std::string>;
using VL = std::vector<long long>;
using VVL = std::vector<VL>;
using VVVL = std::vector<VVL>;
using VD = std::vector<double>;
template <class T>
using V = std::vector<T>;

/* using std */
using std::cout;
constexpr char endl = '\n';
using std::bitset;
using std::cin;
using std::list;
using std::map;
using std::multimap;
using std::multiset;
using std::pair;
using std::priority_queue;
using std::queue;
using std::set;
using std::stack;
using std::string;
using std::unordered_map;
using std::unordered_multimap;
using std::unordered_multiset;
using std::unordered_set;
using std::vector;

/* Initial processing  */
struct Preprocessing {
  Preprocessing() {
    std::cin.tie(0);
    std::ios::sync_with_stdio(0);
  };
} _Preprocessing;

/* Remove the source of the bug */
signed pow(signed, signed) {
  assert(false);
  return -1;
}

/* define hash */
namespace std {
template <>
class hash<std::pair<ll, ll>> {
 public:
  size_t operator()(const std::pair<ll, ll>& x) const {
    return hash<ll>()(1000000000 * x.first + x.second);
  }
};
}  // namespace std

/* input */
template <class T>
std::istream& operator>>(std::istream& is, vector<T>& vec) {
  for (T& x : vec) is >> x;
  return is;
}

/* constant value */
// constexpr ll MOD = 1000000007;
constexpr ll MOD = 998244353;

//=============================================================================================
template <class Lambda>
auto graphBFS(long long n,
	      const std::unordered_multimap<long long, long long>& graph,
	      long long root, const Lambda& lambda) {
  V<bool> isUsed(n, false);
  isUsed[root] = true;
  std::queue<long long> q;
  q.emplace(root);
  while (!q.empty()) {
    auto from = q.front();
    q.pop();

    auto range = graph.equal_range(from);
    REPI2(itr, range.first, range.second) {
      auto to = itr->second;
      if (!isUsed[to]) {
	q.emplace(to);
	isUsed[to] = true;
	lambda(from, to);
      }
    }
  }
}

template <class TYPE = long long, class Lambda>
auto binarySearch(const TYPE& mn, const TYPE& mx, const Lambda& judge,
		  bool rev = false) {
  auto ok = mx;
  auto ng = mn - 1;
  while (ok - ng > 1) {
    auto mid = (ok + ng) / 2;
    auto isOk = judge(mid);
    if ((isOk && !rev) || (!isOk && rev)) {
      ok = mid;
    } else {
      ng = mid;
    }
  }
  return ok;
}
signed main() {
  ll n;
  cin >> n;
  VL x(n), y(n);
  REP(i, n) {
    ll a, b;
    cin >> a >> b;
    x[i] = a;
    y[i] = b;
  }

  auto ans = binarySearch<ll>(1, 2e8, [&](ll mid) {
    unordered_multimap<ll, ll> graph;
    ll t = 10 * mid;
    REP(i, n)
    FOR(j, i + 1, n)
    if ((x[i] - x[j]) * (x[i] - x[j]) + (y[i] - y[j]) * (y[i] - y[j]) <=
	t * t) {
      graph.emplace(i, j);
      graph.emplace(j, i);
    }
    bool ok = false;
    graphBFS(n, graph, 0, [&](ll from, ll to) {
      if (to == n - 1) {
	ok = true;
      }
    });
    return ok;
  });
  cout << ans * 10 << endl;
}