#include "bits/stdc++.h" using namespace std; using Graph = vector>; typedef long long ll; typedef pair P; #define rep(i,n) for (ll i = 0; i < (n); ++i) #define all(x) (x).begin(), (x).end() #define rall(x) (x).rbegin(), (x).rend() const long long mod = 1e9 + 7; ll gcd(ll a, ll b) { return b ? gcd(b, a % b) : a; } ll lcm(ll a, ll b) { return a / gcd(a, b) * b; } int main() { ll x, y, l; cin >> x >> y >> l; ll turn=0; ll move=0; if (y > 0) { move += (y+l-1)/l; } else if (y < 0) { turn = 2; move += (abs(y) + l - 1) / l; } if (x != 0) { turn=1; move += (abs(x) + l - 1) / l; } ll ans = move + turn; cout << ans << endl; }