#include <bits/stdc++.h>
using namespace std;

#define rep(i, n) for (int i = 0; i < n; i++)
#define all(x) (x).begin(),(x).end()
const int mod = 998244353;
const int Mod = 1000000007;
const long long INF = 1LL << 60;
using ll = long long;
using ld = long double;
#define v2d(type,H,W,name,value) vector<vector<type>> name(H,vector<type>(W,value));

int main()
{
  ll N;
  cin >> N;

  ll ans=0;

  for(int i=2;i*i<=N;i++){
    while(!(N%i)){
      ans+=i;
      N/=i;
    }
  }

  if(N>1) ans+=N;
  cout << ans << endl;
}