#include <iostream>
#include <vector>
using namespace std;
using ll = long long;

int x, y, h;

vector<vector<int>> mem;

int f(int a, int b){
    if(mem[a][b] != -1) return mem[a][b];
    mem[a][b] = a+b;
    ll nh = h;
    for(int i = 0; i < a+b; i++) nh *= 2;
    for(int i = 0; i < a; i++) nh *= 2;
    if(1LL*x*1000 > nh) mem[a][b] = max(mem[a][b], f(a+1, b));
    for(int i = 0; i < a; i++) nh /= 2;
    for(int i = 0; i < b; i++) nh *= 2;
    if(1LL*y*1000 > nh) mem[a][b] = max(mem[a][b], f(a, b+1));
    return mem[a][b];
}

int main(){
    mem = vector<vector<int>>(50, vector<int>(50, -1));
    cin >> x >> y >> h;
    cout << f(0, 0) << endl;
    return 0;
}