#include <bits/stdc++.h>
#define rep(i, n) for (int i = 0; i < (n); i++)
using namespace std;
typedef long long ll;

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