import sys
#sys.setrecursionlimit(10 ** 6)
INF = float('inf')
#10**20,2**63に変えるのもあり
MOD = 10**9 + 7
MOD2 = 998244353
from collections import defaultdict
def solve():
    def II(): return int(sys.stdin.readline())
    def LI(): return list(map(int, sys.stdin.readline().split()))
    def LC(): return list(input())
    def IC(): return [int(c) for c in input()]
    def MI(): return map(int, sys.stdin.readline().split())
    N = II()
    def prime_factorize(n):
        a = []
        while n % 2 == 0:
            a.append(2)
            n //= 2
        f = 3
        while f * f <= n:
            if n % f == 0:
                a.append(f)
                n //= f
            else:
                f += 2
        if n != 1:
            a.append(n)
        return a
    Div = prime_factorize(N)
    L = len(Div)
    #print(Div)
    print(sum(Div))
    return
solve()