#define rep(i,n) for(int i=0;i<(int)(n);i++)
#define ALL(v) v.begin(),v.end()
typedef long long ll;
 
#include<bits/stdc++.h>
using namespace std;
 
int main(){
  ios::sync_with_stdio(false);
  std::cin.tie(nullptr);
  
  int x,y,l;
  cin>>x>>y>>l;
  int a=(abs(x)+l-1)/l,b=(abs(y)+l-1)/l;
  if(x==0 && y==0) cout<<4<<endl;
  else if(x==0 && y>0) cout<<b<<endl;
  else if(x==0) cout<<b+2<<endl;
  else if(y==0) cout<<a+1<<endl;
  else if(y>0) cout<<a+b+1<<endl;
  else cout<<a+b+2<<endl;
  
  return 0;
}