use std::collections::VecDeque;

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

    let mut result = 0.;
    let mut deque = VecDeque::new();
    result += 1. / 3.;
    deque.push_back((1. / 3., 0, p0));
    for _ in 0..20 {
        let limit = deque.len();
        for _ in 0..limit {
            let (prob, pattern, prevp) = deque.pop_front().unwrap();
            let p = if pattern == 0 { prevp } else if pattern == 1 { prevp - q } else { prevp + q };
            let p = p.max(0.).min(1.0);
            // used + win
            result += prob * p * 0.5;
            // unused + win
            result += prob * (1. - p) / 3.;
            // used + even
            deque.push_back((prob * p * 0.5, 1, p));
            // unused + even
            deque.push_back((prob * (1. - p) / 3., 2, p));
        }
    }
    println!("{}", result);
}