#include <iostream>
#include <string>
#include <vector>
#include <algorithm>
using namespace std;
using i32 = int32_t;
using u32 = uint32_t;
using i64 = int64_t;
using u64 = uint64_t;
#define rep(i,n) for(int i=0; i<(n); i++)


vector<pair<u64,u64>> factorize(u64 n){
    vector<pair<u64,u64>> res;
    for(u64 i=2; i*i<=n; i++){
        if(n%i) continue;
        res.push_back({i,0});
        while(n%i==0){ n/=i; res.back().second++; }
    }
    if(n!=1) res.push_back({n,1});
    return res;
}


int main(){
    int N; cin >> N;
    auto F = factorize(N);
    u64 ans = 0;
    for (auto& f : F) ans += f.first * f.second;
    cout << ans << endl;
    return 0;
}




struct ios_do_not_sync {
    ios_do_not_sync() {
        ios::sync_with_stdio(false);
        cin.tie(nullptr);
    }
} ios_do_not_sync_instance;