fn main() {
    let mut s = String::new();
    std::io::stdin().read_line(&mut s).ok();
    std::io::stdin().read_line(&mut s).ok();
    let n: Vec<u64> = s.split_whitespace().flat_map(str::parse).collect();
    println!("{}", 2 * n[0] * n[1] * n[2] / (n[1] + n[2]))
}