fn main() {
    let mut d = String::new();
    std::io::stdin().read_line(&mut d).ok();
    let d: usize = d.trim().parse().unwrap();

    let result: String = (d * 108).to_string();
    let (natural, decimal) = result.split_at(result.len() - 2);
    println!("{}.{}", natural, decimal);
}