#include <iostream>
using namespace std;

int main() {
  long double x, y, h;
  cin >> x >> y >> h;
  x *= 1000; y*= 1000;
  int ans = 0;
  while(x > h) {
    x /= 2;
    h *= 2;
    ans++;
  }
  while(y > h) {
    y /= 2;
    h *= 2;
    ans++;
  }
  cout << ans << endl;
}