using System;
using System.Collections.Generic;
using System.Text;
using System.Linq;
 
class Program
{
    public void Proc()
    {
        Reader.IsDebug = false;
        int numCount = int.Parse(Reader.ReadLine());
        ulong ans = ulong.MaxValue;
        for(int i=0; i<numCount; i++) {
            ans = Math.Min(ans, this.Conv(Reader.ReadLine()));
        }
        Console.WriteLine(ans.ToString("#####################################0"));
        

        
    }
    
    private ulong Conv(string strNum) {
        char maxC = strNum.Max();
        uint baseNum = 2;
        if(maxC <= '9') {
            baseNum = uint.Parse(maxC.ToString());
        } else
        {
            baseNum = (uint)(10 + (maxC - 'A'));
        }
        baseNum++;
        baseNum = Math.Max(2, baseNum);
        
        ulong pow = 1;
        ulong val = 0;
        for(int i=0; i<strNum.Length; i++) {
            if(i>0) {
                pow = pow * baseNum;
            }
            char ketaC = strNum[strNum.Length - 1 - i];
            uint ketaNum = 0;
            if(ketaC <= '9') {
                ketaNum = uint.Parse(ketaC.ToString());
            } else
            {
                ketaNum = (uint)(ketaC - 'A' + 10);
            }
            val += (ketaNum * pow);
        }
        return val;
    }


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




1
0XFFFFFFFFFF





 
";
        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();
    }
}