#include <algorithm>
#include <array>
#include <cmath>
#include <cstdio>
#include <deque>
#include <iomanip>
#include <iostream>
#include <numeric>
#include <optional>
#include <queue>
#include <set>
#include <unordered_map>
#include <unordered_set>
#include <vector>

using namespace std;

int main() {
    int64_t n;
    cin >> n;
    int64_t ans = 0;
    for (auto i = int64_t(1); i * i <= n; ++i) {
        if (n % i != 0)
            continue;
        ans += i;
        ans += n / i;
        if (i * i == n)
            ans -= i;
    }
    cout << ans << endl;
    return 0;
}