fn main() {
    input! {
        n: usize,
        p: f64,
        q: f64,
    }
    if p == 1.0 {
        println!("1");
        return;
    }
    let f = |(a, b): (f64, f64), (c, d): (f64, f64)| -> (f64, f64) {
        (a * c / (1.0 - b * d), b + a * a * d / (1.0 - b * d))
    };
    let mut n = n;
    let mut r = (q, p);
    let mut t = (1.0, 0.0);
    while n > 0 {
        if n & 1 == 1 {
            t = f(t, r);
        }
        r = f(r, r);
        n >>= 1;
    }
    println!("{}", t.1);
}

/*

通過確率a, 戻る確率b

(a,b) * (c, d)

A = ac sum_{i >= 0} (db)^i = ac/(1-db)
左右対称

B = b + a^2 d sum_{i>=0}(db)^i
= b+a^2d/(1-bd)
対称じゃない

左右で通過、戻るを持てばok

いや今回は同じ門の連打しかないからこれでいい

*/

// ---------- begin input macro ----------
// reference: https://qiita.com/tanakh/items/0ba42c7ca36cd29d0ac8
#[macro_export]
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_export]
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_export]
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 ----------