import java.util.Scanner;

public class Main {
	public static void main(String[] args) {
		new Main().run();
	}

	void run() {
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();
		double r = sc.nextDouble();
		double t = sc.nextDouble();
		double[] a = { r, t };
		double[] ans = { 0, 1 };
		for (; n > 0; n >>= 1, a = merge(a, a)) {
			if (n % 2 == 1) {
				ans = merge(ans, a);
			}
		}
		System.out.println(ans[0]);
	}

	double[] merge(double[] a, double[] b) {
		double[] ret = { a[0] + a[1] * a[1] * b[0] / (1 - a[0] * b[0]), a[1] * b[1] / (1 - a[0] * b[0]) };
		return ret;
	}

}