#include<iostream>
#include<map>
#include<vector>
#include <algorithm>
#include<math.h>
#include <iomanip>
#include<set>
#include <numeric>
using namespace std;


int main()
{
    long long n, sum1 = 0;
    cin >> n;
    int t = pow(n, 0.5);
    for (long long i = 1; i <= t; i++){
        if (!(n%i) && (i != n/i)) sum1 += (i + n/i);
        else if (!(n%i))sum1 += i;
    }
    cout << sum1 << endl;
}