#include<bits/stdc++.h>
using namespace std;
using Int = long long;
template<typename T1,typename T2> inline void chmin(T1 &a,T2 b){if(a>b) a=b;}
template<typename T1,typename T2> inline void chmax(T1 &a,T2 b){if(a<b) a=b;}

//INSERT ABOVE HERE
signed main(){
  Int n;
  cin>>n;
  Int ans=0;
  for(Int i=1;i*i<=n;i++){
    if(n%i) continue;
    ans+=i;
    if(i*i!=n) ans+=n/i;
  }
  cout<<ans<<endl;
  return 0;
}