import java.util.*;
         
class Main{
    public static void main(String[] args) {
        
        try(Scanner sc = new Scanner(System.in)){
 
            int tate = Integer.parseInt(sc.next()) * 1000;
            int yoko = Integer.parseInt(sc.next()) * 1000;
            int atsumi = Integer.parseInt(sc.next());

            int count = 0;

            while(tate > atsumi || yoko > atsumi){
                if(tate > yoko){
                    tate = tate /2;
                    atsumi = atsumi * 2;
                } else {
                    yoko = yoko /2;
                    atsumi = atsumi * 2;
                } 
                count++;
            }

            System.out.println(count);

        }catch(Exception e){
            e.printStackTrace();
        }        
    }
}