using System;

namespace ConsoleApp29
{
    class Program
    {
        static void Main(string[] args)
        {
            string[] row = Console.ReadLine().Split();

            int x = int.Parse(row[0]);
            int y = int.Parse(row[1]);
            int r = int.Parse(row[2]);

            int M = (int)Math.Ceiling(Math.Abs(x) + Math.Abs(y) + r * Math.Sqrt(2));

            Console.WriteLine(M);
        }
    }
}