#include<iostream>
#include<stdio.h>
#include<algorithm>
#include<vector>
#include<string.h>
#include<math.h>
#include<map>
#include<iomanip>
#include<queue>

using namespace std;

int main(){
	long long x,y,l;
	cin >> x >> y >> l;
	
	long long ans=0;
	
	if(x!=0)ans+=1;
	
	if(y<0 && x==0)ans+=2;
	else if(y<0 && x!=0)ans+=1;
		
	x=abs(x);
	y=abs(y);
	
	ans+=(x+l-1)/l;
	ans+=(y+l-1)/l;
	
	cout << ans << endl;
	
	return 0;
}