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

namespace ConsoleApplication6
{
    class Program
    {
        static void Main(string[] args)
        {
            string[] A = Console.ReadLine().Split();
            int x = int.Parse(A[0]);
            x = Math.Abs(x);
            int y = int.Parse(A[1]);
            y = Math.Abs(y);
            int r = int.Parse(A[2]);

            int ans = (int)(x + y + r * Math.Sqrt(2) + 1);

            Console.WriteLine(ans);
        }
    }
}