#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define N 100000
ll sum(ll n){
    ll ans=0;
    for(int i=1;i*i<=n;i++){
            if(n%i==0){
                ans+=i;
                if(i!=n/i){
                    ans+=n/i;
                }
            }
    }

    return ans;
}
int main(){
	//freopen("stdin.inp","r",stdin);
	//freopen("stdout.out","w",stdout);

	//Your code here
    ll n;
    cin>>n;
    cout<<sum(n)<<endl;

	return 0;
}