#include <iostream>
#define int long long
using namespace std;

signed main() {
	int no;
	
	cin >> no;
	
	int doga, wa = 0;
	for (doga = 1; doga * doga < no; doga++) {
		int ka = no % doga;
		if (ka == 0) {
			wa += doga + no / doga;
		}
	}
	if (doga * doga == no) {
		wa += doga;
	}
	
	int ita = printf("%lld\n", wa);
	return !ita;
}