using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace foryuki
{
    class Program
    {
        static void Main(string[] args)
        {
            int[] c = ConvertStringArrayToIntArray(Console.ReadLine().Split());
            Array.Sort(c);

            while (c[2] - c[0] > 2)
            {
                c[2] -= 2;
                c[0] += 1;
                Array.Sort(c);
            }
            Console.WriteLine(c.Min());
        }

        //-------------------------------------------------------------

        static int[] ConvertStringArrayToIntArray(string[] str)
        {
            int[] b = Array.ConvertAll<string, int>(str, delegate(string value)
                {
                    return int.Parse(value);
                });
            return b;
        }

        static List<int> ConvertStringArrayToIntList(string[] str)
        {
            var list = new List<int>();
            foreach (var c in str)
            {
                list.Add(int.Parse(c));
            }
            return list;
        }
    }
}