#include <iostream>		//cin, cout
#include <vector>		//vector
#include <algorithm>	//sort,min,max,count
#include <string>		//string,getline, to_string
#include <cstdlib>		//abs(int)
#include <utility>		//swap, pair
#include <deque>		//deque
#include <climits>		//INT_MAX
#include <bitset>		//bitset

using namespace std;

int main() {

	int X, Y, L;
	cin >> X >> Y >> L;

	int a = (abs(X) + L - 1) / L;
	int b = (abs(Y) + L - 1) / L;

	int ans;

	if (X == 0 && Y == 0) {
		ans = 0;
	}
	else if (X == 0 && Y > 0) {
		ans = b;
	}
	else if (X > 0 && Y > 0) {
		ans = a + b + 1;
	}
	else if (X > 0 && Y == 0) {
		ans = a + 1;
	}
	else if (X > 0 && Y < 0) {
		ans = a + b + 2;
	}
	else if (X == 0 && Y < 0) {
		ans = b + 2;
	}
	else if (X < 0 && Y < 0) {
		ans = a + b + 2;
	}
	else if (X < 0 && Y == 0) {
		ans = a + 1;
	}
	else {
		ans = a + b + 1;
	}

	cout << ans << endl;
	
	return 0;

}