use std::io::{self, BufRead};

fn get_lines() -> Vec<String> {
    let stdin = io::stdin();
    let lines: Vec<String> = stdin.lock().lines().map(|l| l.unwrap()).collect();
    return lines;
}

fn main(){
    let s = &get_lines()[0];
    let n: i64 = s.parse().unwrap();
    println!("{}", ((n / 3) + (n / 5)) * 2);
}