using System;
using System.Collections.Generic;
using System.Text;

class Program
{
    public void Proc()
    {
        Reader.IsDebug = false;
        List<int> numList = new List<int>();
        numList.AddRange(Reader.GetInt());
        numList.Sort();


        // 要分配
        while (numList[2] - numList[0] > 2)
        {
            if (numList[2] - numList[1] > 4 && numList[1] - numList[0] <= 1)
            {
                // 一番大きいものから小さいもの2つへ
                int must = (numList[2] - numList[1]) / 5;
                numList[2] -= must * 4;
                numList[1] += must;
                numList[0] += must;
            }
            else if (numList[1] - numList[0] > 3 && numList[2] - numList[1] <= 1)
            {
                // 大きいもの２つから一番小さいものへ
                int must = (numList[1] - numList[0]) / 4;
                if (must == 0)
                {
                    break;
                }
                numList[2] -= must * 2;
                numList[1] -= must * 2;
                numList[0] += must * 2;
            }
            else
            {
                // 一番大きいものから小さいものへ
                if (numList[2] - numList[1] <= 1)
                {
                    numList[2] -= 2;
                    numList[0] += 1;
                }
                else
                {
                    int must = Math.Min((numList[2] - numList[1]) / 2, numList[1] - numList[0]);
                    if (must == 0)
                    {
                        break;
                    }
                    numList[2] -= must * 2;
                    numList[0] += must;
                }

            }
            numList.Sort();
        }
        numList.Sort();
        Console.WriteLine(numList[0]);

    
    }



    public class Reader
    {
        public static bool IsDebug = true;
        private static String PlainInput = @"

7777777 3 9999999





 
";
        private static System.IO.StringReader Sr = null;
        public static string ReadLine()
        {
            if (IsDebug)
            {
                if (Sr == null)
                {
                    Sr = new System.IO.StringReader(PlainInput.Trim());
                }
                return Sr.ReadLine();
            }
            else
            {
                return Console.ReadLine();
            }
        }
        public static int[] GetInt(char delimiter = ' ', bool trim = false)
        {
            string inptStr = ReadLine();
            if (trim)
            {
                inptStr = inptStr.Trim();
            }
            string[] inpt = inptStr.Split(delimiter);
            int[] ret = new int[inpt.Length];
            for (int i = 0; i < inpt.Length; i++)
            {
                ret[i] = int.Parse(inpt[i]);
            }
            return ret;
        }
    }
    static void Main()
    {
        Program prg = new Program();
        prg.Proc();
    }
}