#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<ll,ll> P;
ll x,y,h;
ll ans;
int main(void){
    cin.tie(0);
    ios::sync_with_stdio(0);
    cin>>x>>y>>h;
    x*=1000;
    y*=1000;
    while(x>h){
        x/=2;
        h*=2;
        ans++;
    }
    while(y>h){
        y/=2;
        h*=2;
        ans++;
    }
    cout<<ans<<endl;

}