#include<bits/stdc++.h>
using namespace std;
long long ans = 0, n;
int main()
{
    cin >> n;
    int k = sqrt(n);
    for(int i = 1; i <= k; ++i) if(n % i == 0) ans += i + n / i;
    if(k * k == n) cout << ans - k;
    else cout << ans;
    cout << '\n';
}