#include <bits/stdc++.h>
using namespace std;
double const eps = 1e-10;

int main() {
    double x,y,h; cin >> x >> y >> h;
    x *= 1000; y *= 1000;
    
    if(x > y) swap(x,y);
    int res = 0;
    while(x > h + eps) {
        ++res; x *= 0.5; h *= 2.0;
    }
    while(y > h + eps) {
        ++res; y *= 0.5; h *= 2.0;
    }
    cout << res << endl;
}