#include <bits/stdc++.h>
using namespace std;int main(){int a,b=0,c=0;cin>>a;for(;c<=a/2;b+=a%++c?0:c);cout<<b+a;}

#include <iostream>
using namespace std;
int main()
{
long long a=1,x,sum;
cin>>x;
while( a<=x )
{
if(x%a==0)
sum=sum+a;
a=a+1;
}
sum=sum;
cout<<sum<<endl;
return 0;
}

#include <iostream>
using namespace std;
int main()
{
int a,b,bb=1,d=0;
cin>>a;

while(bb<=a)
{
if(a%bb==0)
d=d+bb;

bb++;
}

cout<<d;

return 0;
}