using System;
using System.Collections.Generic;

class program
{
    public static void Main()
    {
        var N = int.Parse(Console.ReadLine());
        var V = new string[N];
        for (var i = 0; i < N; i++)
        {
            V[i] = Console.ReadLine();

            var buf = 0;
            for (var j = 0; j < V[i].Length; j++)
            {
                if (!(V[i][j] == '0'))
                {
                    buf = j;
                    break;
                }
            }
            V[i] = V[i].Substring(buf, V[i].Length - buf);
        }

        var minVal = V[0];
        for (var i = 1; i < N; i++)
        {
            if (minVal.CompareTo(V[i]) > 0 && minVal.Length >= V[i].Length)
            {
                minVal = V[i];
            }
        }

        var sinsu = (int)'0';
        
        foreach(var s in minVal.ToCharArray()){
            if (sinsu < s) sinsu = s;
        }

        if (sinsu >= 'A')
        {
            sinsu -= (int)'A' + 10;
        }
        else
        {
            sinsu -= (int)'0';
        }

        var result = 0.0;
        for (int i = 0; i < minVal.Length; i++)
        {
            var c = (int)minVal[i];
            if (c >= 'A')
            {
                c -= (int)'A' + 10;
            }else{
                c -= (int)'0';
            }

            result += Math.Pow((double)sinsu + 1, minVal.Length - i - 1) * c;

        }

        Console.WriteLine(result);
    }
}