use std::io::Read;
use std::collections::HashSet;

fn solve(n: usize) {
    let mut yakusuu = HashSet::new();
    for i in 1..(((n as f64).powf(0.5) as usize) + 1) {
        if n % i == 0 {
            yakusuu.insert(i);
            yakusuu.insert(n / i);
        }
    }
    println!("{}", yakusuu.iter().sum::<usize>());
}

fn main() {
    let mut n = String::new();
    std::io::stdin().read_to_string(&mut n).ok();
    let n: usize = n.trim().split('\n').next().unwrap().trim().parse::<usize>().unwrap();
    solve(n);
}