import java.util.*;

public class Main {
    public static void main(String[] args) throws Exception {
        Scanner sc=new Scanner(System.in);
        double X=sc.nextDouble();
        double Y=sc.nextDouble();
        double H=sc.nextDouble();
        
        X*=1000;
        Y*=1000;
        
        if(X<Y){// X,Y must be X>Y
            double tmp=X;
            X=Y;
            Y=tmp;
        }
        
        int ans=0;
        
        while(Y>H){
            ans++;
            Y/=2;
            H*=2;
        }
        
        while(X>H){
            ans++;
            X/=2;
            H*=2;
        }
        
        System.out.println(ans);
    }
}