#include <bits/stdc++.h>
using namespace std;
#define all(x) x.begin(),x.end()
#define rep(i, n) for (int i = 0; i < (int)(n); i++)
template<class T> inline bool chmax(T&a,T b){if(a<b){a=b;return 1;}return 0;}
template<class T> inline bool chmin(T&a,T b){if(a>b){a=b;return 1;}return 0;}
using ll = long long;

int x,y,l;

int main(){
    cin >> x >> y >> l;
    cout << (abs(x)+l-1)/l+(abs(y)+l-1)/l+(y<0 ? 2 : !!x) << endl;
}