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 minVal = int.MaxValue;
        var minpos = 0;
        for (var i = 0; i < N; i++)
        {
            var rep = 0.0;
            for (var j = 0; j < V[i].Length; j++)
            {
                var c = (int)V[i][j];
                if (c >= 'A')
                {
                    c -= (int)'A';
                    c += 10;
                }
                else
                {
                    c -= (int)'0';
                }
                rep += Math.Pow(36, V[i].Length - j - 1) * c;
            }

            if (rep < minVal)
            {
                minVal = (int)rep;
                minpos = i;
            }
        }

        var k = (int)'0';
        foreach (var c in V[minpos])
        {
            k = k < c ? c : k;
        }

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

        double result = 0;
        for (var i = 0; i < V[minpos].Length; i++)
        {
            var c = (int)V[minpos][i];
            if (c >= 'A')
            {
                c -= (int)'A';
                c += 10;
            }
            else
            {
                c -= (int)'0';
            }
            result += Math.Pow(k, V[minpos].Length - i - 1) * c;
        }
        Console.WriteLine((long)result);
    }
}