using System.Numerics;

public class Program
{
    public static void Main()
    {
        //Biginteger num =BigInteger.Parse(Console.ReadLine() ?? string.Empty);
        string[] str = (Console.ReadLine() ?? string.Empty).Trim().Split(' ');
        //string str = Console.ReadLine() ?? string.Empty;


        BigInteger ho1 =BigInteger.Parse(str[0]);
       BigInteger ho2 =BigInteger.Parse(str[1]);
       BigInteger final =BigInteger.Parse(str[2]);

        BigInteger a = final;
        if(ho1 <= final)
        {
            a--;
        }
        if(ho2 <= final)
        {
            a--;
        }
        Console.WriteLine(a);

    }
}