#include<stdio.h>
int main(){
	long int X,Y,L,i=0,j=0,ans=0,flag=0;
	scanf("%ld%ld%ld",&X,&Y,&L);

	if(X<0){
		X=-X;
		i++;
	}
	if(Y<0){
		Y=-Y;
		j++;
	}

	if(X%L==0)
		ans=ans+X/L;
	else
		ans=ans+X/L+1;
	if(Y%L==0)
		ans=ans+Y/L;
	else
		ans=ans+Y/L+1;

	if(X==0){
		if(j==0)
			ans++;
	}
	if(j!=0)
		ans+=2;
	

printf("%ld\n",ans);
	return 0;
}