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

namespace No172
{
	class MainClass
	{
		public static void Main (string[] args)
		{
			var line = Console.ReadLine ().Split (' ').Select (v => Convert.ToInt32 (v)).ToArray ();
			var x = Math.Abs(line [0]);
			var y = Math.Abs(line [1]);
			var r = line [2];
			var s = x + y + r * Math.Sqrt(2);
			Console.WriteLine (((int)Math.Ceiling(s)).ToString ());
		}
	}
}