#include<iostream>
using namespace std;
double x,y,h;
main()
{
	cin>>x>>y>>h;
	int ans=0;
	x*=1000;
	y*=1000;
	if(x>y)
	{
		double t=x;
		x=y;
		y=t;
	}
	while(x-1e-10>h)
	{
		x/=2;
		h*=2;
		ans++;
	}
	while(y-1e-10>h)
	{
		y/=2;
		h*=2;
		ans++;
	}
	cout<<ans<<endl;
}