#include <iostream>

using namespace std;

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

	cin >> X >> Y >> L;


	int stepx, stepy;
	int rot;

	stepx = abs(X) / L + ( abs(X)%L==0?0:1 );
	stepy = abs(Y) / L + ( abs(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 = 2;

	} 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 = 1;
	} else if( X <  0 && Y >  0 ) {
		rot = 1;
	}

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

	
	return 0;
}