// ---------- begin input macro ----------
// reference: https://qiita.com/tanakh/items/0ba42c7ca36cd29d0ac8
macro_rules! input {
    (source = $s:expr, $($r:tt)*) => {
        let mut iter = $s.split_whitespace();
        input_inner!{iter, $($r)*}
    };
    ($($r:tt)*) => {
        let s = {
            use std::io::Read;
            let mut s = String::new();
            std::io::stdin().read_to_string(&mut s).unwrap();
            s
        };
        let mut iter = s.split_whitespace();
        input_inner!{iter, $($r)*}
    };
}

macro_rules! input_inner {
    ($iter:expr) => {};
    ($iter:expr, ) => {};
    ($iter:expr, $var:ident : $t:tt $($r:tt)*) => {
        let $var = read_value!($iter, $t);
        input_inner!{$iter $($r)*}
    };
}

macro_rules! read_value {
    ($iter:expr, ( $($t:tt),* )) => {
        ( $(read_value!($iter, $t)),* )
    };
    ($iter:expr, [ $t:tt ; $len:expr ]) => {
        (0..$len).map(|_| read_value!($iter, $t)).collect::<Vec<_>>()
    };
    ($iter:expr, chars) => {
        read_value!($iter, String).chars().collect::<Vec<char>>()
    };
    ($iter:expr, bytes) => {
        read_value!($iter, String).bytes().collect::<Vec<u8>>()
    };
    ($iter:expr, usize1) => {
        read_value!($iter, usize) - 1
    };
    ($iter:expr, $t:ty) => {
        $iter.next().unwrap().parse::<$t>().expect("Parse error")
    };
}
// ---------- end input macro ----------

fn gcd(a: i128, b: i128) -> i128 {
    if b == 0 {
        a
    } else {
        gcd(b, a % b)
    }
}

fn run() {
    input! {
        a: i128,
        b: i128,
    }
    let mut a = a.abs();
    let mut b = b.abs();
    if a < b {
        std::mem::swap(&mut a, &mut b);
    }
    let g = gcd(a, b);
    let mut ans = 0f64;
    if a == 0 {
    } else if (a + b) % 2 == 0 {
        for i in (1..=1000).rev() {
            if i % 2 == 0 {
                let v = (i * g + 2) as f64;
                ans += 1.0 / v.powf(v) * (i + 1) as f64;
            }
        }
    } else {
        for i in (1..=1000).rev() {
            let v = (i * g + 2) as f64;
            ans += 1.0 / v.powf(v) * (i + 1) as f64;
        }
    }
    ans += 0.25;
    println!("{:.7}", ans);
}

fn main() {
    run();
}