n = int(input())
m = n if n % 2 == 1 else int(n / 2)
ret = i = 1
while i * i <= m:
    i += 1
    cnt = 1
    while m % i == 0:
        m /= i
        cnt += 1
    ret *= (i**cnt - 1) / (i - 1)
ret *= m + 1 if m > 1 else 1
print(int(ret))