#include<iostream>
#include<string>
#include<math.h>
#include<stdlib.h>
using namespace std;

int main() {
	int x, y, z,sum;
	sum = 0;
	cin >> x >> y >> z;
	if (abs(x) % z == 0) {
		sum = sum + abs(x) / z;
	}
	else{
		sum = sum + abs(x) / z + 1;
	}
	if (abs(y) % z == 0) {
		sum = sum + abs(y) / z;
	}
	else {
		sum = sum + abs(y) / z + 1;
	}
	if (y >= 0) {
		if (x != 0) {
			sum = sum + 1;
		}
	}
	else {
		sum = sum + 2;
	}
	cout << sum;
}