#include <iomanip>
#include <iostream>

using ldouble = long double;

const ldouble EPS = 1e-10;

int main() {
    std::cout << std::fixed << std::setprecision(10);

    int N;
    ldouble p, q;
    std::cin >> N >> p >> q;

    if (p < EPS || 1 - p < EPS) {
        std::cout << p << std::endl;
        return 0;
    }

    ldouble ans = p;
    for (int i = 0; i < N - 1; ++i) {
        ans = ans * q * q / (1 - p * ans) + p;
    }

    std::cout << ans << std::endl;
    return 0;
}