def sum_of_divisors(n):
    if n == 0:
        return 0
    factors = {}
    # Factor out 2s
    while n % 2 == 0:
        factors[2] = factors.get(2, 0) + 1
        n = n // 2
    # Factor for odd numbers starting from 3
    i = 3
    max_factor = int(n**0.5) + 1
    while i <= max_factor and n > 1:
        while n % i == 0:
            factors[i] = factors.get(i, 0) + 1
            n = n // i
            max_factor = int(n**0.5) + 1
        i += 2
    if n > 1:
        factors[n] = 1
    # Calculate the sum of divisors
    total = 1
    for p, exp in factors.items():
        total *= (p**(exp + 1) - 1) // (p - 1)
    return total

N = int(input())
if N % 2 == 0:
    d = N // 2
else:
    d = N

print(sum_of_divisors(d))