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 mother = p * q + (1 - p) * (1 - q);
        double ans = p * q / mother;
        System.out.println(java.math.BigDecimal.valueOf(ans * 100).toPlainString());
    }
}