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 % 7] as char); } let _ = "0.1428571428571428571428571428571428571428571428571428571428571428571428571428571428571428571428571428"; // println!("{}", x.len()); println!(); }