#include<iostream>
#include<cstdio>
#include<string>
#include<vector>
#include<queue>
#include<set>
#include<sstream>
#include<algorithm>
using namespace std;

#define ALL(x) (x).begin(),(x).end()
#define RALL(x) (x).rbegin(), (x).rend()
#define SORT(x) sort((x).sbegin(), (x).end())
#define rep(i,n) for(int i=0;i<n;i++)
#define rev(j,m) for(int j=1;j<=m;j++)

typedef vector<pair<int,int> > pii;


int main(){
	long long int x,y,a,xc=0;
	cin >> x >> y >> a;
	
	if(abs(x)%a!=0)xc++;
	if(abs(y)%a!=0)xc++;
	
	if(y<0)xc+=2;
	else if(x!=0)xc++;
	
	cout << abs(x)/a+abs(y)/a+xc << endl;
	
	return 0;
}