use std::io::*;

fn rec(sai: &[usize], res: &mut Vec<usize>, v: usize, c: usize, n: usize) {
    if c == n {
        res.push(v);
        return;
    }
    for i in 0..sai.len() {
        rec(&sai, res, v * sai[i], c + 1, n);
    }
}

fn main() {
    let mut s: String = String::new();
    std::io::stdin().read_to_string(&mut s).ok();
    let mut itr = s.trim().split_whitespace();
    let p: usize = itr.next().unwrap().parse().unwrap();
    let c: usize = itr.next().unwrap().parse().unwrap();

    let sai1: Vec<usize> = [2, 3, 5, 7, 11, 13].to_vec();
    let sai2: Vec<usize> = [4, 6, 8, 9, 10, 12].to_vec();
    let mut ans = 0;
    let all = 6usize.pow((p + c) as u32);

    let mut a = Vec::new();
    let mut b = Vec::new();
    rec(&sai1, &mut a, 1, 0, p);
    rec(&sai2, &mut b, 1, 0, c);
    for i in 0..a.len() {
        for j in 0..b.len() {
            ans += a[i] * b[j];
        }
    }
    println!("{:.10}", ans as f64 / all as f64);
}