using System;

internal class Program
{
    private static void Main(string[] args)
    {
        var abcArr = Console.ReadLine().Split(' ');
        var a = int.Parse(abcArr[0]);
        var b = int.Parse(abcArr[1]);
        var c = int.Parse(abcArr[2]);

        var result = Math.Min(a, b);

        var difAB = Math.Max(a, b) - result;

        if (difAB < c)
        {
            result += difAB + ((c - difAB) / 2);
        }
        else
        {
            result += c;
        }

        Console.Write(result);
    }
}