#include <iostream>
#include <cmath>
using namespace std;

long long tongUoc(long long n) {
    long long sum = 0;
   
    for (long long i = 1; i  <= sqrt(n); i++) {
        if (n % i == 0) {
            sum+= i; 
            if (i != n / i) {
                sum+= n / i; 
            }
        }
    }
    return sum;
}

int main() {
    long long n;
    cin >> n;

    cout << tongUoc(n) << endl;

    return 0;
}