#include <bits/stdc++.h>
using namespace std;

using ll = long long int;

int main(){
    ll x, y, h;
    cin >> x >> y >> h;
    if(x > y) swap(x,y);
    x *= 1000;
    y *= 1000;
    ll ans = 0, ht = h;
    while(x > ht){
        ht <<= 2;
        ans++;
    }
    ht = (h << ans);
    while(y > ht){
        ht <<= 2;
        ans++;
    }
    cout << ans << endl;
    return 0;
}