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

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

	map<int, int> mp;
	for( int i = 2; i * i <= N; i++ ) {
		while( N % i == 0 ) {
			mp[i]++;
			N /= i;
		}
	}
	if( N != 1 ) mp[N]++;

	int ans = 0;
	for( auto it = mp.begin(); it != mp.end(); it++ ) {
		ans += it->first * it->second;
	}

	cout << ans << endl;
}