use std::io::{Read,stdin};

fn main() {
    let mut buf = String::new();
    stdin().read_to_string(&mut buf).unwrap();
    let mut tok = buf.split_whitespace();
    let mut get = || tok.next().unwrap();
    macro_rules! get {
        ($t:ty) => (get().parse::<$t>().unwrap());
        () => (get!(i64));
    }
    
    let n = get!(usize);
    
    print!("0");
    
    if n > 1 {
        print!(".");
    }
    
    for i in 0..n {
        print!("{}", b"142857"[i % 6] as char);
    }
    
    let _ = "0.1428571428571428571428571428571428571428571428571428571428571428571428571428571428571428571428571428";
    
    // println!("{}", x.len());
    
    println!();
}