def midPositiveElement(a):
    pos = [x for x in a if x > 0]
    mid = (len(pos) - 1) // 2
    return pos[mid]

#include <iostream>
#include <cmath>
using namespace std;

long long ss(long long n) {
    long long sum = 0;

    if (n % 2 == 0) {
        sum += 2; 
        while (n % 2 == 0) {
            n /= 2;
        }
    }

    for (long long i = 3; i <= sqrt(n); i += 2) {
        if (n % i == 0) {
            sum += i; 
            while (n % i == 0) {
                n /= i;
            }
        }
    }
    if (n > 1) {
        sum += n;
    }

    return sum;
}

int main() {
    long long n;
    cin >> n;
    cout << ss(n) << endl;
    return 0;
}

class UserMainCode(object):
    @classmethod
    def bestFibo(cls, input1):
        cnt = 0
        ans = 0

        for i in input1:
            if i == "H": 
                ans += 2
                cnt += 1
            else:  
                ans -= 1

            if cnt >= 3:
                break

        return ans

SELECT c.name AS Country, SUM(g.goals) AS Goals
FROM Countries c
JOIN Goals g ON c.id = g.country_id
GROUP BY c.id, c.name
ORDER BY Goals DESC, c.id ASC

long getMaxProfit(vector<int> pnl, int k) {
    int n = pnl.size();
    long maxprofit = 0;
    int i;
    long profit = 0;
    int start = 0;
    for(i=0;i<n;i++) {
        profit += pnl[i];
        if (profit <= 0) {
            profit = 0;
            start = i+1;
        } else {
            maxprofit = max(maxprofit , profit);
            if (i-start+1 == k) {
               
                profit -= pnl[start];
                start++;
            }
            while(pnl[start] <= 0 && start <=i) {
                profit -= pnl[start];
                maxprofit = max(maxprofit , profit);
                start++;
            }
        }
    }
    return maxprofit;
}