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

namespace yukicodeX {
    public class ProgramX {
        public static int Solver(System.IO.TextReader reader) {
            var buf = reader.ReadLine().Split();
            var x = int.Parse( buf[ 0 ] );
            var y = int.Parse( buf[ 1 ] );
            var r = int.Parse( buf[ 2 ] );
            return ( x >= 0 ? x : -x ) + ( y >= 0 ? y : -y ) + (int)( r / Math.Sqrt( 2 ) * 2 + 1 );
        }

        private static void Main() {
            Console.WriteLine( Solver( Console.In ) );
        }
    }
}