#include <bits/stdc++.h>

#define REP(i, x, n) for(int i = x; i < (int)(n); i++)
#define rep(i, n) REP(i, 0, n)
#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()
#define F first
#define S second
#define mp make_pair

using namespace std;

typedef long long ll;
typedef unsigned long long ull;
typedef pair<int, int> P;

int N;
double X[1000], Y[1000];
bool visited[1000];
bool flg;

void rec(int idx, double L) {
  visited[idx] = true;
  
  if(idx == N - 1) {
    flg = true;
  }

  if(flg) return;

  rep(i, N) {
    if(i == idx || visited[i]) continue;
    if(pow(X[i] - X[idx], 2) + pow(Y[i] - Y[idx], 2) <= L * L) {
      rec(i, L);
    }
  }
}

int main() {
  // ios_base::sync_with_stdio(false);
  cin >> N;
  rep(i, N) cin >> X[i] >> Y[i];

  double lb = 0;
  double ub = 1e9 + 10;

  rep(i, 100) {
    double mid = (lb + ub) / 2;
    memset(visited, false, sizeof(visited));
    flg = false;
    rec(0, mid);
    if(flg) ub = mid;
    else lb = mid;
  }

  int ans = 0;
  for(int i = 10; i <= 1e9 + 10; i += 10) {
    ans = i;
    if(i > ub) break;
  }

  cout << ans << endl;
  
  return 0;
}