fn main() {
    let k = read::<i64>();
    let mut ans = 0.0;
    for i in 1..15 {
        ans += ((k * i) as f64).sin() / (i as i64).pow(i as u32) as f64;
    }
    println!("{}", ans);
}

fn read<T: std::str::FromStr>() -> T {
    let mut s = String::new();
    std::io::stdin().read_line(&mut s).ok();
    s.trim().parse().ok().unwrap()
}