#include <iostream>
#include <vector>
#include <algorithm>
#include <cmath>
#define rep(i, a, n) for(int i = a; i < n; i++)
using namespace std;
using ll = long long;
using P = pair<int, int>;

int main()
{
    double x, y, h;
    cin >> x >> y >> h;
    int ans = 0;
    double X = 1000*x, Y = 1000*y;
    while(X > h || Y > h){
        if(X > h){
            X /= 2;
            h *= 2;
        }
        else{
            Y /= 2;
            h *= 2;
        }
        //cout << X << " " << Y << endl;
    
        ans++;
    }
    cout << ans << endl;
    return 0;
}