using System;
using System.Collections.Generic;
using System.Text;
using System.Linq;
 
class Program
{
    public void Proc()
    {
        Reader.IsDebug = false;
        int pointCount = int.Parse(Reader.ReadLine());
        
        List<Pos> lst = new List<Pos>();
        
        for(int i=0; i<pointCount; i++) {
            lst.Add(new Pos(Reader.ReadLine()));
        }
        
        long ans = long.MinValue;
        for(int i=0; i<pointCount; i++) {
           ans = Math.Max(ans, lst.Where(a=>a != lst[i]).Min(a=>   (a.X - lst[i].X) *  (a.X - lst[i].X)  + (a.Y - lst[i].Y) * (a.Y - lst[i].Y) ));
        }
        double tmp = Math.Sqrt((ans / 100d));
        Console.WriteLine(Math.Ceiling(tmp) * 10);

    }
    
    public class Pos {
        public long X;
        public long Y;
        
        public Pos(string init) {
            string[] inpt = init.Split(' ');
            this.X = long.Parse(inpt[0]);
            this.Y = long.Parse(inpt[1]);
        }
    }


    public class Reader
    {
        public static bool IsDebug = true;
        private static String PlainInput = @"




3
0 0
10 10
15 14



 
";
        private static System.IO.StringReader Sr = null;
        public static string ReadLine()
        {
            if (IsDebug)
            {
                if (Sr == null)
                {
                    Sr = new System.IO.StringReader(PlainInput.Trim());
                }
                return Sr.ReadLine();
            }
            else
            {
                return Console.ReadLine();
            }
        }
        public static int[] GetInt(char delimiter = ' ', bool trim = false)
        {
            string inptStr = ReadLine();
            if (trim)
            {
                inptStr = inptStr.Trim();
            }
            string[] inpt = inptStr.Split(delimiter);
            int[] ret = new int[inpt.Length];
            for (int i = 0; i < inpt.Length; i++)
            {
                ret[i] = int.Parse(inpt[i]);
            }
            return ret;
        }
    }
    static void Main()
    {
        Program prg = new Program();
        prg.Proc();
    }
}