#include <iostream>

using namespace std;

int main()
{
	int X, Y, L;

	cin >> X >> Y >> L;


	int stepx, stepy;
	int rot;

	stepx = abs(X) / L + ( X%L==0?0:1 );
	stepy = abs(Y) / L + ( Y%L==0?0:1 );
	if( X == 0 && Y == 0 ) {
		rot = 0;
	} else if( X == 0 && Y > 0 ) {
		rot = 0;
	} else if( X >  0 && Y > 0 ) {
		rot = 1;
	} else if( X >  0 && Y == 0 ) {
		rot = 1;
	} else if( X >  0 && Y <  0 ) {
		rot = 2;
	} else if( X == 0 && Y <  0 ) {
		rot = 2;
	} else if( X <  0 && Y <  0 ) {
		rot = 3;
	} else if( X <  0 && Y == 0 ) {
		rot = 3;
	} else if( X <  0 && Y >  0 ) {
		rot = 3;
	}

	//cout << stepx << endl;
	//cout << stepy << endl;
	//cout << rot   << endl;
	cout << stepx+stepy+rot << endl;

	
	return 0;
}