#include<iostream>
#include<cmath>
using namespace std;

int main(){
	int x, y, l;
	cin >> x >> y >> l;

	int xl = abs(x)/l,
		yl = abs(y)/l;
	
	
	if(x%l != 0) xl += 1;
	if(y%l != 0) yl += 1;

	int dir = 0;
	if(y < 0) dir += 2;
	if(x != 0) dir += 1;

	cout << dir + xl + yl << endl;
}