class Program
{
    static void Main(string[] args)
    {
        string[] input = Console.ReadLine()!.Split(' ');
        int red = int.Parse(input[0]);
        int blue = int.Parse(input[1]);
        int white = int.Parse(input[2]);

        if (red > blue)
        {
            int tmp = red;
            red = blue;
            blue = tmp;
        }

        int num = blue - red;
        int ans = white - num;

        if (num > white)
        {
            Console.WriteLine(red + white);
        }
        else if (red == 0 && white == 0 || blue == 0 && white == 0)
        {
            Console.WriteLine(0);
        }
        else
        {
            Console.WriteLine(ans / 2 + num + red);
        }
    }
}