#include<iostream>
using namespace std;

int main(){
    double x,y,h;
    int cnt=0;
    cin>>x>>y>>h;
    h/=1000;
    while(true){
        if(x<=h&&y<=h)break;
        else{
            if(x>y){
                if(y>h)y/=2;
                else x/=2;
            }else{
                if(x>h)x/=2;
                else y/=2;
            }
            h*=2;
            cnt++;
        }
    }
    cout<<cnt<<endl;
    return 0;
}