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;

        Console.WriteLine(ans / 2 + num + red);
    }
}