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

    let mut answer = vec!['0'];
    if n > 0 {
        answer.extend(['.']);
        answer.extend(['1', '4', '2', '8', '5', '7'].repeat(n / 6));
        answer.extend(['1', '4', '2', '8', '5', '7'].iter().take(n % 6));
    }
    let answer: String = answer.iter().collect();

    println!("{answer}");
}