#include "bits/stdc++.h"
using namespace std;
#define int long long
#define REP(i, n) for (int i = 0; i < (int)(n); ++i)
#define RREP(i, n) for (int i = (int)n - 1; i >= 0; --i)
#define FOR(i, s, n) for (int i = s; i < (int)n; ++i)
#define RFOR(i, s, n) for (int i = (int)n - 1; i >= s; --i)
#define ALL(a) a.begin(), a.end()
#define IN(a, x, b) (a <= x && x < b)
template<class T>inline bool CHMIN(T&a,T b){if(a>b){a = b;return true;}return false;}
template<class T>inline bool CHMAX(T&a,T b){if(a<b){a = b;return true;}return false;}

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