fn main() {
    let mut pq = String::new();
    std::io::stdin().read_line(&mut pq).ok();
    let pq: Vec<f64> = pq.trim().split_whitespace().map(|s| s.parse().unwrap()).collect();
    let p = pq[0] / 100.;
    let q = pq[1] / 100.;

    let result = p * q / (p * q + (1. - p) * (1. - q));
    println!("{}", result * 100.);
}