import math 

def divSum() :
    num = int(input())
    if num == 1: 
        print(1)
        exit()
    result = 0
    i = 2
    while i*i <= num: 
        if (num % i == 0): 
            if (i == (num // i)): 
                result += i 
            else : 
                result += i + num//i
        i += 1
    print(int(1 + result + num))
divSum()