import java.util.*;
public class Test10 {
  public static void main(String[] args){
    Scanner sc=new Scanner(System.in);
    String[] line;
    line=sc.nextLine().split(" ");
    int x=Integer.parseInt(line[0]);
    int y=Integer.parseInt(line[1]);
    int r=Integer.parseInt(line[2]);
    int dist=Math.abs(x)+Math.abs(y)+(int)(r*Math.sqrt(2))+1;
    System.out.println(dist);
    sc.close();
  }
}