#include <bits/stdc++.h>
using namespace std;
#define FOR(i,a,b) for(int i=(a);i<(b);++i)
#define REP(i,n) FOR(i,0,n)
#define ALL(v) begin(v),end(v)
template<typename A, typename B> inline bool chmax(A & a, const B & b) { if (a < b) { a = b; return true; } return false; }
template<typename A, typename B> inline bool chmin(A & a, const B & b) { if (a > b) { a = b; return true; } return false; }
using ll = long long;
using pii = pair<int, int>;
constexpr ll INF = 1ll<<30;
constexpr ll longINF = 1ll<<60;
constexpr ll MOD = 1000000007;
constexpr bool debug = false;
//---------------------------------//

int main() {
	ll X, Y, H;
	cin >> X >> Y >> H;
	if (X < Y) swap(X, Y);
	X *= 1000;
	Y *= 1000;
	int x = 0, y = 0;
	while (X > H || Y > H) {
		if (X > H) ++x;
		if (Y > H) ++y;
		H <<= 1;
	}
	int cx = (x + 1) / 2;
	int cy = (y - cx + 1) / 2;
	cout << cx + cy << endl;
}