import java.math.BigInteger;
import java.util.*;
public class Main {
	public static void main(String[] args) {
		Scanner sc=new Scanner(System.in);
		int n=sc.nextInt();
		int m = sc.nextInt();
		int r = sc.nextInt();
		double waa = 1/Math.sqrt(2);
		System.out.println(Math.abs(n)+Math.abs(m)+(int)(Math.ceil(r/waa)));
	}
}