#include <iostream>
using namespace std;
using ll = long long int;

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