#include<bits/stdc++.h>
using namespace std;
int main(){
    long x,y,h;
    cin >> x >> y >> h;
    double xx = (double)x * 1000.0;
    double yy = (double)y * 1000.0;
    if(xx>yy)swap(xx,yy);
    int ans = 0;
    while(xx > h){
        xx /= 2.0;
        h *= 2;
        ans++;
    }
    while(yy > h){
        yy /= 2.0;
        h *= 2;
        ans++;
    }
    cout<<ans<<endl;
}