import std.conv, std.functional, std.stdio, std.string;
import std.algorithm, std.array, std.bigint, std.container, std.math, std.numeric, std.range, std.regex, std.typecons;
import core.bitop;

class EOFException : Throwable { this() { super("EOF"); } }
string[] tokens;
string readToken() { for (; tokens.empty; ) { if (stdin.eof) { throw new EOFException; } tokens = readln.split; } auto token = tokens.front; tokens.popFront; return token; }
int readInt() { return readToken.to!int; }
long readLong() { return readToken.to!long; }
real readReal() { return readToken.to!real; }

bool chmin(T)(ref T t, in T f) { if (t > f) { t = f; return true; } else { return false; } }
bool chmax(T)(ref T t, in T f) { if (t < f) { t = f; return true; } else { return false; } }

int binarySearch(alias pred, T)(in T[] as) { int lo = -1, hi = cast(int)(as.length); for (; lo + 1 < hi; ) { const mid = (lo + hi) >> 1; (unaryFun!pred(as[mid]) ? hi : lo) = mid; } return hi; }
int lowerBound(T)(in T[] as, T val) { return as.binarySearch!(a => (a >= val)); }
int upperBound(T)(in T[] as, T val) { return as.binarySearch!(a => (a > val)); }


enum LIM = 3 * 10L^^8;

int N;
long[] X, Y;

void main() {
  try {
    for (; ; ) {
      N = readInt();
      X = new long[N];
      Y = new long[N];
      foreach (u; 0 .. N) {
        X[u] = readLong();
        Y[u] = readLong();
      }
      
      auto C = new long[][](N, N);
      foreach (u; 0 .. N) foreach (v; u + 1 .. N) {
        const d2 = (X[u] - X[v])^^2 + (Y[u] - Y[v])^^2;
        long lo = 0, hi = LIM;
        for (; lo + 1 < hi; ) {
          const mid = (lo + hi) / 2;
          (d2 <= (10L * mid)^^2) ? (hi = mid) : (lo = mid);
        }
        C[u][v] = C[v][u] = 10L * hi;
      }
      debug {
        writeln("C = ", C);
      }
      
      auto d = new long[N];
      auto vis = new bool[N];
      d[] = 10L * LIM;
      d[0] = 0;
      foreach (_; 0 .. N) {
        int um = -1;
        foreach (u; 0 .. N) {
          if (!vis[u]) {
            if (um == -1 || d[um] > d[u]) {
              um = u;
            }
          }
        }
        vis[um] = true;
        foreach (v; 0 .. N) {
          chmin(d[v], max(d[um], C[um][v]));
        }
      }
      writeln(d[N - 1]);
    }
  } catch (EOFException e) {
  }
}