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

struct UnionFind {
  vector< int > par;
  UnionFind(int n = 1) {
    init(n);
  }

  void init(int n = 1) {
    par.resize(n);
    for(int i = 0; i < n; i++)
      par[i] = -1;
  }
  
  int root(int n) {
    if (par[n] < 0) return n;
    return par[n] = root(par[n]);
  }

  bool merge(int x, int y) {
    x = root(x); y = root(y);
    if (x == y) return false;
    if (par[x] > par[y]) swap(x, y);
    par[x] += par[y];
    par[y] = x;

    return true;
  }

  bool issame(int x, int y) {
    return root(x) == root(y);
  }
};

int main() {
  int n;
  cin >> n;
  vector< int64_t > x(n), y(n); 
  for (int i=0; i<n; ++i) cin >> x[i] >> y[i];
  
  vector< vector< int64_t > > d(n, vector< int64_t >(n, 0));
  for (int i=0; i<n; ++i) {
    for (int j=0; j<n; ++j) {
      d[i][j] = (x[i]-x[j])*(x[i]-x[j]) + (y[i]-y[j])*(y[i]-y[j]);
    }
  }

  
  auto check = [&](int64_t k) {
    UnionFind uf(n+1);
    for (int i=0; i<n; ++i) {
      for (int j=0; j<n; ++j) {
        if (d[i][j] <= k*k*100) uf.merge(i, j); 
      }
    }
    return uf.issame(0, n-1);    
  };
  
  // 範囲は[ng, ok). 
  int64_t ng = 0LL, ok = 1e9+1;
  while (ok-ng > 1LL) {
    int64_t mid = (ok+ng)/2;
    (check(mid) ? ok : ng) = mid;
  }
  int64_t ans = ok * 10LL;
  cout << ans << endl;

  return 0;
}