use std::{collections::HashSet, io};

fn main() {
    let mut n = String::new();
    io::stdin().read_line(&mut n).ok();
    let n = n.trim().parse::<u64>().unwrap();

    let mut possible = HashSet::new();
    for p in [2, 3, 5, 7, 11, 13] {
        for c in [4, 6, 8, 9, 10, 12] {
            possible.insert(p * c);
        }
    }

    if possible.contains(&n) {
        println!("{}", 36f64.recip());
    } else {
        println!("0");
    }
}