2-0-2-5.cpp

#include <iostream>
using namespace std;

int main() {
	int n, sum = 0;
	cin >> n;
	for (int i = 1; i <= n / 2; i++) {
		if (n % i == 0) {
			sum += i;
		}
	}
	cout << sum << endl;
	return 0;
}