#include<bits/stdc++.h>
using namespace std;
 
typedef long long ll;
typedef vector<pair<ll, ll>> pll;
 
#define mod 1000000007
#define all(x) (x).begin(), (x).end()
#define pb push_back
#define popcount(x) __builtin_popcountll(x)
 
const long double PI = acos(-1);
 
ll gcd(ll a,ll b){return b ? gcd(b,a%b) : a;}
ll lcm(ll a,ll b){return a / gcd(a,b) * b;}
ll stringcount(string s, char c){return count(s.cbegin(), s.cend(), c);}
bool isInteger(double x){return floor(x) == x;}

int main(){
  ios::sync_with_stdio(false);
  cin.tie(0);

  double x, y, h;
  cin >> x >> y >> h;

  h /= 1000;

  ll ans = 0;
  while(1){
    if(x <= h && y <= h) break;

    if(x - h < y - h && x > h || y <= h){
      x /= 2;
      h *= 2;
      ans++;
    }else if(y > h){
      y /= 2;
      h *= 2;
      ans++;
    }
    //cout << x << " " << y << " " << h << endl;
  }
  cout << ans << endl;
  return 0;
}