using System;
using System.Numerics;
using System.Text;

class PetersGame
{
    static void Main()
    {
        BigInteger starting = BigInteger.Parse(Console.ReadLine()); //10
        BigInteger end = BigInteger.Parse(Console.ReadLine()); //14
        string replacement = Console.ReadLine(); //a

        BigInteger sum = 0;
        string replays = string.Empty;
        string result = string.Empty;

        for (BigInteger i = starting; i < end; i++)
        {
            if (i % 5 == 0)
            {
                sum += i;
            }
            else
            {
                sum += i % 5;
            }

            if (sum % 2 == 0)
            {
                replays = sum.ToString()[0].ToString();
            }
            else
            {
                replays = sum.ToString()[sum.ToString().Length - 1].ToString();
            }

            result = sum.ToString().Replace(replays, replacement);
        }

        Console.WriteLine(result);
    }
}