def divisors(n):
    divs = []
    for d in range(1, int(n**0.5) + 1):
        if n % d == 0:
            divs.append(d)
            q = n // d
            if q != d:
                divs.append(q)
    return divs


def max_div(n):
    l, r = 1, n + 1
    while r - l > 1:
        m = (l + r) // 2
        if m * m <= n:
            l = m
        else:
            r = m
    return l


def divisors2(n):
    divs = []
    # lim = int(n**0.5)
    lim = max_div(n)
    d = 1
    while d <= lim:
        if n % d == 0:
            divs.append(d)
            q = n // d
            if q != d:
                divs.append(q)
        d += 1
    return divs


print(sum(divisors2(int(input()))))