#include <bits/stdc++.h>

using namespace std;

typedef unsigned long long ull;
typedef long long ll;

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