fn main() {
    let mut s = String::new();
    std::io::stdin().read_line(&mut s).ok();
    let n = s.trim().parse::<i32>().unwrap();

    let mut ans = 0;
    for t in 0..=n / 5 {
        for c in 0..=t {
            if (n - 5 * t - 2 * c).max(-1) % 3 == 0 {
                ans += 1;
            }
        }
    }
    println!("{}", ans);
}