#include <cstdio>
#include <iostream>
#include <string>
#include <vector>
#include <sstream>
#include <map>
#include <set>
#include <queue>
#include <algorithm>
#include <cmath>
#include <cstring>
#include <typeinfo>
#include <numeric>
#include <functional>
#include <unordered_map>
#include <bitset>
#include <stack>
#include <assert.h>
#include <unordered_set>
#include <random>


using namespace std;
using ll = long long;
using ull = unsigned long long;

const ll INF = 1e18;
const ll MOD = 1e9 + 7;

#define REP(i, n) for(ll i = 0; i < n; i++)













 
int main(){
    long double x, y, h;
    cin >> x >> y >> h;
    h /= 1000.0;
    if(x > y) swap(x, y);
    ll cnt = 0;
    while(x > h){
        x /= 2.0;
        h *= 2.0;
        cnt++;
    }
    while(y > h){
        y /= 2.0;
        h *= 2.0;
        cnt++;
    }
    cout << cnt << endl;
}