#include <bits/stdc++.h>

int go_forward(int dest_pos, int allowed_distance) {
	int dest_pos_abs = std::abs(dest_pos);
	if (dest_pos_abs <= allowed_distance) {
		return 1;
	}
	int mod = dest_pos_abs % allowed_distance;
	int quo = dest_pos_abs / allowed_distance;
	return (mod == 0) ? quo : quo + 1;
}

int main(int argc, char *argv[]) {
    int dest_x = 0;
    int dest_y = 0;
	int allowed_distance = 0;
	int order_count = 0;

	std::cin >> dest_x;
	std::cin >> dest_y;
	std::cin >> allowed_distance;

	//  y axis
	if (dest_y != 0) {
		if (dest_y < 0) {
			order_count += 2;
		}
		order_count += go_forward(dest_y, allowed_distance);
	}

	//  x axis
	if (dest_x != 0) {
		order_count += 1;
		order_count += go_forward(dest_x, allowed_distance);
	}

	std::cout << order_count << std::endl;
	return 0;
}