#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;

vector<int> factor(int n){
	vector<int>ret;
	while(n%2==0){
		ret.push_back(2);
		n/=2;
	}
    for(int i=3;i*i<n;i+=2){
    	while(n%i==0){
    		ret.push_back(i);
    		n/=i;
    	}
    }
    if(n!=1) ret.push_back(n);
	return ret;
}

int main() {
    int n; cin>>n;
    int ans = 0;
    for(int m: factor(n)) ans+=m;
    cout << ans << endl;
    return 0;
}