import java.util.Arrays;
import java.util.LinkedList;
import java.util.Scanner;

public class Main {
	
	public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
		
		final long X = sc.nextLong();
		final long Y = sc.nextLong();
		final long L = sc.nextLong();
		
		System.out.println(((Math.abs(X) / L) + (Math.abs(X) % L != 0 ? 1 : 0)) + ((Math.abs(Y) / L) + (Math.abs(Y) % L != 0 ? 1 : 0)) + (Y < 0 ? 2 : 1));
		
	}
	
}