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()
}

fn main() {
  let n: usize = read();
  println!("{:.2}", no285(n));
}

fn no285(d: usize) -> f64 {
  (d as f64) * 1.08
}