use std::collections::VecDeque;


fn main() {
    let mut temp = String::new();
    std::io::stdin().read_line(&mut temp).ok();
    let temp: Vec<f64> = temp.trim().split_whitespace().map(|s| s.parse().unwrap()).collect();
    let p0 = temp[0] / 100.;
    let q = temp[1] / 100.;

    let mut result = 1. / 3.;
    let mut deque = VecDeque::new();
    deque.push_back((1. / 3., 1, p0));
    while let Some((prob, pattern, prevp)) = deque.pop_front() {
        if prob < 1e-12 { continue; }
        let p = match pattern {
            1 => { prevp },
            2 => { (prevp+q).min(1.) },
            3 => { (prevp-q).max(0.) },
            _ => { unreachable!() }
        };

        let eq = prob * p / 2.;
        result += eq;
        deque.push_back((eq, 3, p));

        let eq = prob * (1. - p) / 3.;
        result += eq;
        deque.push_back((eq, 2, p));
    }
    println!("{}", result);
}