import math
def divSum(num) :

    result = 0
    i = 2
    while i<= (math.sqrt(num)) :

        if (num % i == 0) :

            if (i == (num / i)) :
                result = result + i;
            else :
                result = result + (i + num/i);
        i = i + 1

    return (result + 1)+num;

num = int(input())
a = divSum(num)
print(int(a))