import java.util.*;

public class Main {
	public static void main (String[] args) {
		Scanner sc = new Scanner(System.in);
		double p = sc.nextDouble() / 100.0;
		double q = sc.nextDouble() / 100.0;
		double r = p * q / (p * q + (1 - p) * (1 - q)) * 100;
		System.out.println(java.math.BigDecimal.valueOf(r).toPlainString());
    }
}