#include <iostream>

using namespace std;

int afford_year(double salary, double price, int current_year = 1, double current_money = 0) {
    if ((current_money += salary) >= price) { return current_year; }
    if (current_year > 100) { return -1; }
    return afford_year(salary * 1.08, price * 1.10, current_year + 1, current_money);
}

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

    double money, price;
    int ans;
    cin >> money >> price;

    if ((ans = afford_year(money, price)) == -1) {
        cout << "Forget it." << endl;
    } else {
        cout << ans << endl;
    }

    return 0;
}