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