#include<bits/stdc++.h>

using namespace std;
using ll=long long;
#define rep2(i, a, n) for(int i = (a); i < (n); i++)
#define rep(i, n) rep2(i,0,n)

int main(){
  cin.tie(nullptr);ios_base::sync_with_stdio(false);
  ll n,a=2;cin>>n;
  vector<ll> ret;
  for(int64_t a=1;a*a<=n;a++){
    if(n%a==0){
      ret.push_back(a);
      if(a*a!=n) ret.push_back(n/a);
    }
  }
  sort(ret.begin(),ret.end());
  ll cnt=0;
	for(auto&& e:ret) cnt+=e;
  cout<<cnt<<endl;
}