#include <bits/stdc++.h>
using namespace std;
int main(){
 long long N;
 cin>>N;
 long long D=sqrt(N);
 long long answer=0;
 for(int i=1;i<=D;i++){
   if(N%i==0)answer=answer+i+N/i;
 }
 if(D*D==N)answer=answer-D;
cout<<answer;

}