#include <bits/stdc++.h>
using namespace std::literals::string_literals;
using i64 = long long;
using std::cout;
using std::endl;
using std::cin;

template<typename T>
std::vector<T> make_v(size_t a){return std::vector<T>(a);}

template<typename T,typename... Ts>
auto make_v(size_t a,Ts... ts){
  return std::vector<decltype(make_v<T>(ts...))>(a,make_v<T>(ts...));
}

int main() {
	i64 n; scanf("%lld", &n);

	i64 ans = 0;
	for(i64 i = 1; i * i <= n; i++) {
		if(n % i) continue;
		
		ans += (i == n / i ? i : i + n / i);
	}
	printf("%lld\n", ans);
	return 0;
}