#include<iostream>
#include<vector>
#include<algorithm>
#include<queue>
#include<cmath>
#include<iomanip>
#include<map>
#include<cstring>

using namespace std;

#define rep(i, n) for (int i = 0; i < (int)(n); i++)
#define vi vector<int>
#define vivi vector<vi>
const int INF = int(1e9);
typedef long long int ll;
/* -- template -- */

int main(){
    double x, y, h;
    cin >> x >> y >> h;
    h /= 1000;
    int count = 0;
    while(x > h || y > h){
        if(x > y && y > h){
            y /= 2;
            h *= 2;
        }else{
            x /= 2;
            h *= 2;
        }
        ++count;
    }
    cout << count;
}