#include <iostream>

using lint = long long;

void solve() {
    lint x, y, h;
    std::cin >> x >> y >> h;
    x *= 1000, y *= 1000;

    if (x > y) std::swap(x, y);

    int ans = 0;

    lint dx = 1;
    while (x > h * dx) {
        h *= 2;
        dx *= 2;
        ++ans;
    }

    lint dy = 1;
    while (y > h * dy) {
        h *= 2;
        dy *= 2;
        ++ans;
    }

    std::cout << ans << std::endl;
}

int main() {
    std::cin.tie(nullptr);
    std::ios::sync_with_stdio(false);

    solve();

    return 0;
}