#include <cstdio>
using namespace std;
int n, ans;
int main() {
	freopen("factor.in", "r", stdin);
	freopen("factor.out", "w", stdout);
	scanf("%d", &n);
	if (n == 1) {
		printf("1");
		return 0;
	}
	for (int i = 1; i * i <= n; i++)
	    if (!(n % i)) {
	    	ans += i;
	    	if (i * i != n)
	    	    ans += n / i;
		}
	printf("%d", ans);
	return 0;
}