#define _GLIBCXX_DEBUG
#define ll long long
#include <bits/stdc++.h>
using namespace std;
using Graph = vector<vector<int>>;

void print(auto a){
  cout << a;
}

void printL(auto a){
  cout << a << endl;
}

void fix(int n){
  cout << fixed << setprecision(n);
}

ll turn(ll x, ll y){
  if(y < 0) return 2;
  else if(x != 0) return 1; 
  else return 0;
}

ll Mv(ll a, ll l){
  if(a < 0) a *= -1;
  return (a+l-1)/l;
}

int main(){
  ll X, Y, L; cin >> X >> Y >> L;
  ll ans = 0;
  ans += turn(X, Y);
  ans += Mv(X, L);
  ans += Mv(Y, L);
  printL(ans);
}