#include <bits/stdc++.h>
#define rep(i, n) for (ll i = 0; i < n; ++i)
typedef long long ll;
using namespace std;
const int INF = 1e9;

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

    ll ans = 0;
    for (ll i = 1; i * i <= n; ++i) {
        if (n % i == 0) {
            if (i == n / i)
                ans += i;
            else
                ans += i + n / i;
        }
    }
    cout << ans << endl;

    return 0;
}