fn run() {
    let mut s = String::new();
    std::io::stdin().read_line(&mut s).unwrap();
    let n: u64 = s.trim().parse().unwrap();
    let mut sum = 0;
    let mut k = 1;
    while k * k < n {
        if n % k == 0 {
            sum += k + n / k;
        }
        k += 1;
    }
    if k * k == n {
        sum += k;
    }
    println!("{}", sum);
}

fn main() {
    run();
}