import java.util.*;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        long n = sc.nextLong();
        if (n <= 2) {
            System.out.println(1);
            return;
        }
        long x;
        if (n % 2 == 0) {
            x = n / 2;
        } else {
            x = n;
        }
        long ans = 1 + x;
        for (long i = 2; i <= Math.sqrt(x); i++) {
            if (x % i == 0) {
                ans += i;
                if (i * i < x) {
                    ans += x / i;
                }
            }
        }
        System.out.println(ans);
    }
}