using System;
using System.IO;
using System.Collections.Generic;
using static System.Console;
using static System.Math;
class Start{
  static void Solve(){
    var x=Abs(Rint());
    var y=Abs(Rint());
    var l=Rint();
    WriteLine((x+l-1)/l+(y+l-1)/l);
  }
  static void Main(){
    READ_COUNT=0;
    READ=In.ReadToEnd().Split(' ','\n');
    var sw=new StreamWriter(OpenStandardOutput()){AutoFlush=false};
    SetOut(sw);
    Solve();
    Out.Flush();
  }
  const long MOD=1000000007L;
  static void Swap<T>(ref T a,ref T b){T c=a;a=b;b=c;}
  static string Read()=>READ[READ_COUNT++];
  static int Rint()=>int.Parse(READ[READ_COUNT++]);
  static long Rlong()=>long.Parse(READ[READ_COUNT++]);
  static double Rdouble()=>double.Parse(READ[READ_COUNT++]);
  static char Rchar()=>READ[READ_COUNT++][0];
  static string[] READ;static int READ_COUNT;
}
class Pair<T1,T2>:IComparable<Pair<T1,T2>>where T1:IComparable<T1>where T2:IComparable<T2>{
  public T1 F;public T2 S;
  public Pair(T1 f,T2 s){F=f;S=s;}
  public int CompareTo(Pair<T1,T2> p)=>F.CompareTo(p.F)!=0?F.CompareTo(p.F):S.CompareTo(p.S);
}