import java.util.*;
import java.io.*;

public class Main {
    public static void main(String[] args) throws Exception {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        long n = Long.parseLong(br.readLine());
        long g;
        if (n % 2 == 0) {
            g = n / 2;
        } else {
            g = n;
        }
        long ans;
        if (g == 1) {
            ans = 1;
        } else {
            ans = g + 1;
        }
        for (long i = 2; i <= Math.sqrt(g); i++) {
            if (g % i == 0) {
                if (i * i == g) {
                    ans += i;
                } else {
                    ans += i;
                    ans += g / i;
                }
            }
        }
        System.out.println(ans);
    }
}