#include<bits/stdc++.h>
#include<iostream>
using namespace std;
using LL = long long;
using P = pair<int,int>;
using Graph = vector<vector<int>>;
const int INF = 1 << 29;
const long long LINF = 1LL << 60;
#define all(x) (x).begin(), (x).end()
#define rep(i,n) for(int i = 0; i < (n); ++i)
template<class T>void chmin(T&a, T b){if(a > b) a = b;}
template<class T>void chmax(T&a, T b){if(a < b) a = b;}

vector<pair<long long, long long>> prime_factorize(long long N){
	vector<pair<long long, long long>> res;
	for(long long a = 2; a * a <= N; ++a){
		if(N%a != 0) continue;
		long long ex = 0;

		while(N % a == 0){
			++ex;
			N /= a;
		}

		res.push_back({a, ex});
	}

	if(N != 1) res.push_back({N, 1});
	return res;
}

int main(){
	//input
	int N; cin >> N;
	if(N == 1){
	   cout << 0 << endl;
	   return 0;
	}
	else{
		long long ans = 0;
		const auto &res = prime_factorize(N);
		for(auto p : res){
			ans += p.first * p.second;
		}
		cout << ans << endl;
	}
}