using System.Linq;
using System;

public class Hello
{
    public static void Main()
    {
        string[] line = Console.ReadLine().Trim().Split(' ');
        var a = Array.ConvertAll(line, int.Parse);
        var amin = a.Min();
        var ans = amin;
        for (int i = 0; i < 3; i++) a[i] -= amin;
        ans += getAns(a);
        Console.WriteLine(ans);
    }
    public static int getAns(int[] a)
    {
        Array.Sort(a);
        var ans = 0;
        while (true)
        {
            if (a[1] == 0) { a[1]++; a[2] -= 2; }
            if (a[2] - 3 < 0) return ans;
            a[2] -= 3;
            a[1]--;
            ans++;
            Array.Sort(a);
        }
    }
}