using System;
using System.Collections.Generic;
using System.Linq;

namespace yukicoder
{
    public class Program
    {
        public static void Main()
        {
            var s = Console.ReadLine().Split(' ').Select(x => int.Parse(x)).ToArray();
            var sum = 0;
            sum = Make(s, sum);
            Console.WriteLine(sum);
        }
        public static int Make(int[] s,int sum)
        {
            while (s.All(x => x > 0))
            {
                s = s.Select(x => x - 1).ToArray();
                sum++;
            }
            if (!s.All(x => x < 3))
            {
                Array.Sort(s);
                s = new int[3] { 1, s[1], s[2] - 2 };
                sum = Make(s, sum);
            }
            return sum;
        }
    }
}